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How to Tell Similar Brick Colors Apart Without Trusting the Screen
Theo Marchetti · · 23 min
What a LEGO color comparison can—and cannot—tell you
An online LEGO colors visual comparison can narrow an unknown piece to a short list. It cannot conclusively identify physical plastic on its own. Treat a screen swatch, rendered thumbnail, or uncontrolled photograph as a way to generate candidates—not as a physical color standard.
The color you see can change because of:
- The intensity and color temperature of the light
- Camera exposure, white balance, compression, and automatic processing
- Display brightness, color profile, calibration, and viewing angle
- Reflections from glossy, curved, or textured surfaces
- Transparency, glitter, metallic particles, pearlescence, or plating
- Material differences between otherwise similar elements
- Yellowing, fading, dirt, ultraviolet exposure, or other aging
- Scratches and changes to the original surface finish
It helps to separate three tasks that are often combined:
- Identifying a physical piece: deciding which color most plausibly describes the brick in your hand.
- Translating catalog terminology: finding the corresponding name or identifier in LEGO Group, BrickLink, Rebrickable, LDraw, BrickOwl, or a historical fan reference.
- Selecting a digital design color: finding a workable catalog shade for an RGB, HEX, rendering, or reference image.
Each task needs different evidence. Physical identification depends primarily on known reference pieces, neutral lighting, element records, and—when available—set inventories. Catalog translation requires explicit cross-references. Digital selection can start with a screen value, but it must still account for finish and element availability.
This guide is therefore a selected comparison framework, not a complete current or historical palette. For close shades, compare the unknown with documented physical examples. Ideally, use the same element in each color. If that is impossible, choose pieces with similar geometry, surface area, material, and gloss. Consistently photographed identical elements are the next-best option when lighting and processing remain unchanged.
Approximate on-screen comparison strip
The swatches below illustrate how a digital comparison can organize candidates. They use database HEX approximations, so they should not be treated as samples of physical plastic.
| Approximate swatch | Rebrickable entry | Digital value | What to compare |
|---|---|---|---|
| Dark Red | #720E0F |
Very dark red; compare against brown or magenta bias | |
| Magenta | #923978 |
More purple-directed than Dark Pink | |
| Dark Pink | #C870A0 |
Lighter and less purple-directed than Magenta | |
| Bright Pink | #E4ADC8 |
Light pink approximation; finish must be checked separately | |
| Medium Lavender | #AC78BA |
More purple-directed than the pink entries | |
| Lavender | #E1D5ED |
Lightest approximation in this selected strip |
These swatches are useful for digital sorting, but their displayed appearance still depends on your screen. The physical piece remains the reference.
Update note: Catalog status, production ranges, database totals, element inventories, and marketplace availability can change. The database checks reflected in this guide are dated August 7, 2026. Recheck mutable records before ordering parts or publishing an inventory.
How the archived Isodomos Color Tree organized the palette
The historical Isodomos Color Tree survives in a Wayback Machine capture dated May 12, 2008. It was a fan-created visual reference, not a current or official LEGO Group publication.
Instead of using one long numerical list, the tree grouped colors into families and arranged them beneath six shade or role columns:
- Dark
- Basic
- Medium
- Light
- Special
- Sand
The visible archived extract contains Gray, Stone Gray, Red, Brown, Tan, Orangish, Orange, Yellow Orange, Yellow, Curry, Lime, Green, Greenish, Turquoise, Royal Blue, and part of Blue. Because the captured extract ends partway through Blue, it cannot establish what appeared in the remainder of the original tree.
Each row paired an upper fan-created name with a lower name and number attributed by the compiler to a LEGO color list. The archive itself warned that its upper-row terms might not be names used by LEGO Group. A fan label can be useful for describing visual relationships without being official product terminology.
| Family | Fan-created name | Attributed LEGO name | Attributed LEGO ID | Archive notation |
|---|---|---|---|---|
| Red | Red | Bright red | 21 | Named pair |
| Red | Sand Red | Sand red | 153 | Named pair in Sand column |
| Green | Sand Green | Sand green | 151 | Named pair in Sand column |
| Stone Gray | Dark Stone Gray | Dark Stone Gray | 199 | Historical named entry |
| Stone Gray | Medium Stone Gray | Medium Stone Gray | 194 | Historical named entry |
| Stone Gray | Light Stone Gray | Light Stone Gray | 208 | Historical named entry |
Source for the historical names, IDs, and notation: the archived Isodomos Color Tree.
The archive used two distinct absence signals:
- A question mark meant that no fan-created match had yet been identified.
- A blank colored entry meant that the compiler knew of no corresponding LEGO-named color.
Those signals are not interchangeable. One marks uncertainty in the fan naming layer; the other marks an absent match in the attributed LEGO-name layer. Modern comparison tables should make the same kind of distinction between “unknown,” “disputed,” and “not recorded” rather than forcing every entry into a one-to-one mapping.
The archived explanation also said that some matching information came from another contributor and treated swatch mismatches as unconfirmed. Its web colors should therefore not be interpreted as definitive physical specifications. The tree is most valuable as a historical organizational model: color families on one axis, shade categories on the other, and two naming systems shown together.
The historical name also requires an entity clarification. The present-day Isodomos About page describes a masonry reference covering brick, concrete block, stone, bond patterns, sizes, and mortars. The available records do not establish that this current masonry site maintains, endorses, owns, or continues the archived LEGO Color Tree.
Why LEGO, BrickLink and Rebrickable names do not always match
There is no universal color number shared by every LEGO-related catalog. LEGO Group, BrickLink, Rebrickable, LDraw, BrickOwl, and historical fan references maintain distinct names and identifiers. Related entries may have substantially different labels even when a database explicitly maps them to one another.
Always preserve the source system:
- LEGO ID 208
- BrickLink ID 99
- Rebrickable ID 320
- LDraw color code, where applicable
A statement such as “color 99” is incomplete because it allows a number from one catalog to be mistaken for a number from another.
The following selected relationships are limited to mappings shown in the cited database records. “Source-confirmed” means that the relationship appears in that source; it does not mean that every catalog defines physical color boundaries identically.
| Relationship status | Catalog A | Catalog B | Interpretation |
|---|---|---|---|
| Source-confirmed mapping | BrickLink White, ID 1 | LEGO White, ID 1 | Same displayed name and number, but the systems should still be labeled |
| Source-confirmed mapping | BrickLink Very Light Gray, ID 49 | LEGO Light Grey, ID 103 | Similar wording, different spelling and ID |
| Source-confirmed mapping | BrickLink Very Light Bluish Gray, ID 99 | LEGO Light Stone Grey, ID 208 | Substantial difference in both name and number |
| BrickLink catalog entry | BrickLink Light Gray, ID 9 | — | Older-gray marketplace entry |
| BrickLink catalog entry | BrickLink Light Bluish Gray, ID 86 | — | Newer bluish-gray marketplace entry |
| BrickLink catalog entry | BrickLink Dark Gray, ID 10 | — | Older dark-gray marketplace entry |
| BrickLink catalog entry | BrickLink Dark Bluish Gray, ID 85 | — | Newer dark bluish-gray marketplace entry |
Source for the BrickLink fields and selected LEGO mappings: BrickLink Color Guide, checked August 7, 2026.
Rebrickable provides another cross-catalog view. The fields below are attributed to Rebrickable rather than presented as direct LEGO Group confirmation.
| Relationship status | Rebrickable entry | LEGO field in Rebrickable | BrickLink field in Rebrickable | Approximate digital value |
|---|---|---|---|---|
| Source-confirmed database cross-reference | Dark Red, ID 320 | Dark red, ID 154 | Dark Red, ID 59 | #720E0F |
| Source-confirmed database cross-reference | Bright Pink, ID 29 | Light Purple, ID 222 | Corresponding catalog entry | #E4ADC8 |
Source for these IDs, names, and RGB approximations: Rebrickable’s color table, checked August 7, 2026.
Bright Pink versus Light Purple shows why a familiar color word is not a stable identifier. Two people can be discussing the same database relationship while using labels that sound as though they belong to different color families.
Useful relationship labels include:
- Source-confirmed mapping: explicitly displayed by a cited catalog.
- Community convention: used for practical communication but not established here as official terminology.
- Historical alias: associated with an older chart or database.
- Conflated marketplace entry: distinctions may be combined for transactions.
- Disputed: sources disagree about equivalence.
- Unknown: no supported mapping is available.
A specialist overview of Brick Colorstream and its companion spreadsheet reports that some marketplace catalogs combine colors for buyer and seller convenience. That can be practical when rare variations are difficult to separate, but it does not prove that the underlying physical colors are identical. The same overview treats consistently photographed pieces, catalog names, identifiers, and historical timelines as complementary evidence rather than one perfect authority in its account of community color references.
For purchasing, search with the marketplace’s own name and ID. For documentation, keep the LEGO field separate when a supported mapping exists. For example:
BrickLink: Very Light Bluish Gray, ID 99 LEGO field in BrickLink: Light Stone Grey, ID 208 Mapping status: source-confirmed in BrickLink Physical identification confidence: probable
This format remains intelligible even if a catalog later changes a display name or classification.
How to compare close colors by hue, saturation and lightness
Color names classify entries; visual characteristics explain why two entries look similar or different.
- Hue is the broad color family or directional bias: red, yellow, green, blue, or a position between them.
- Saturation is color purity or intensity. Highly saturated colors look vivid; low-saturation colors approach gray or muted earth tones.
- Luminance is an approximation of perceived lightness. It does not describe every aspect of vision or reflective plastic.
LEGO pieces reflect light from pigmented plastic. RGB values describe mixtures of red, green, and blue light on a display. A digital value may approximate the result of one rendering or photographic workflow, but it does not specify how plastic will respond to different lights, backgrounds, and viewing angles.
A practical inspection order is:
- Finish and transparency
- Approximate lightness
- Hue bias
- Saturation
- Gloss, texture, wear, and aging
Finish comes first because a transparent pink and a solid pink can produce similar screen colors while behaving very differently in the hand. Glitter, pearl, metallic, chrome, glow, and opal effects introduce additional variables.
Tom Alphin’s controlled-photo analysis used a neutral gray card, extracted RGB values, and converted them to HSL. Within that workflow, bright colors appeared highly saturated while sand colors were lower in saturation. These are measurements from the author’s photographed samples and process, not LEGO Group manufacturing specifications; the method is described in Brick Architect’s color analysis.
RGB and HEX values remain useful for:
- Sorting a digital table
- Finding nearby candidates
- Choosing an initial design-software color
- Creating approximate visual clusters
- Communicating a rendered or photographed target
Label them approximate digital values unless primary evidence establishes otherwise. Do not present third-party RGB, HEX, HSL, CMYK, or Pantone values as official pigment formulas or manufacturing tolerances.
Why matching HEX values can still represent different finishes
Rebrickable records Bright Pink, Trans-Pink, and Glitter Trans-Pink with the same E4ADC8 RGB approximation. It also records Glitter Trans-Dark Pink and Trans-Dark Pink with the same DF6695 approximation. Those shared values do not make the physical entries interchangeable; they show that the color field and the material or finish classification carry different information in the database. Some thumbnails are also rendered or generic rather than photographs of the exact listed material (Rebrickable color table).
A digital collision can be represented like this:
| Displayed swatch | Database entry | Shared approximation | Physical distinction still required |
|---|---|---|---|
| Bright Pink | #E4ADC8 |
Solid | |
| Trans-Pink | #E4ADC8 |
Transparent | |
| Glitter Trans-Pink | #E4ADC8 |
Transparent with glitter |
For dependable comparison, divide candidates into separate groups:
- Solid
- Transparent
- Transparent with glitter
- Pearl
- Metallic
- Chrome or plated
- Glow
- Opal or milky translucent
- Other specialized finishes
Do not rank all finishes in one strip simply because their HEX values are close. Establish the finish class first, then compare lightness, hue bias, and saturation within that class.
A reusable comparison card makes the reasoning visible:
| Field | Example entry |
|---|---|
| Catalog name | Dark Red |
| Catalog system and ID | Rebrickable ID 320 |
| Family | Red |
| Finish | Solid |
| Approximate digital value | #720E0F |
| Source | Rebrickable color table |
| Physical reference | Known plate from a cataloged set |
| Confidence | Probable; agrees with two documented references under neutral light |
| Caveat | Digital value is approximate, not a physical specification |
The confidence note is as important as the swatch. “Supported by set inventory and comparison with two known pieces” communicates more than an isolated colored square. Conversely, “possible match from photograph only” warns a buyer not to order an expensive replacement yet.
Old gray versus bluish gray: the essential close-color test
Old gray and newer bluish gray are among the most consequential distinctions for collectors, builders, and resellers. Third-party accounts differ on whether the change is best summarized as around 2004 or as part of a 2005 palette change. A conservative description is that the transition occurred across approximately 2003–2005, with individual element and set records used to narrow specific cases (New Elementary’s historical overview).
The reported visual cue is hue bias:
- Older Light Gray and Dark Gray: subtly warmer, with a yellow or brown tendency.
- Newer Light Bluish Gray and Dark Bluish Gray: subtly cooler, leaning toward blue.
The distinction may be difficult to see when each piece is viewed alone. It usually becomes clearer when an unknown piece is positioned directly between documented old-gray and bluish-gray references.
Catalog terminology also varies. BrickLink uses “Bluish Gray,” while LEGO-oriented and fan references may use “Stone Grey” or “Stone Gray.” For shared inventories, never record only “new gray.” Include the catalog system and identifier.
| Comparison role | BrickLink name | BrickLink ID | Primary visual cue |
|---|---|---|---|
| Older light gray | Light Gray | 9 | Warmer; less blue |
| Newer light gray | Light Bluish Gray | 86 | Cooler; slightly bluer |
| Older dark gray | Dark Gray | 10 | Warmer or browner |
| Newer dark gray | Dark Bluish Gray | 85 | Cooler or bluer |
Source for the BrickLink names and IDs: BrickLink Color Guide, cited in the cross-reference section above.
In the controlled-photo analysis, the reported saturation was 7% for both newer Light Bluish Gray and Dark Bluish Gray, compared with 2% for old Light Gray and 5% for old Dark Gray. The same analysis placed the older grays toward a yellow-brown hue and the newer versions nearer blue. These figures describe the author’s samples and calibrated-photo workflow, not LEGO manufacturing tolerances (Brick Architect).
Use this physical comparison:
- Place the unknown beside a documented old-gray reference and a documented bluish-gray reference.
- Use diffuse daylight or controlled neutral illumination.
- Place all pieces on a white or neutral gray background.
- Match their orientation so the surfaces catch similar reflections.
- Look first for warmer versus cooler hue bias.
- Treat brightness as a secondary clue.
- Rotate all pieces together to check whether a reflection created the apparent difference.
- Repeat the test under a second neutral light if the result remains ambiguous.
Before comparing visually, narrow the likely production period. A set inventory may sharply reduce the candidate list when it records only one plausible color for that element, although an inventory does not prove the identity of a loose, substituted, or replacement piece. The design’s recorded color range can also eliminate impossible candidates.
Do not infer a corporate rationale from the visible change. The cited third-party sources discuss replacement and palette reduction, but the evidence here is not sufficient to establish LEGO Group’s reasons for making those decisions.
A step-by-step workflow for identifying an unknown piece
The strongest process combines elimination with controlled physical comparison. Do not begin by scrolling through hundreds of swatches and choosing whichever one feels closest.
1. Identify the element or design
Determine what the piece is before trying to name its color. Record its geometry, dimensions, stud arrangement, underside details, and any molded number that helps locate the design in a catalog.
Do not assume that molded numbers are color codes. In one user-generated Eurobricks example, contributors interpreted 3710 as a design ID, 58 as a mold number, and 2 as a position within the mold. That interpretation applies to the discussed example and is community evidence rather than official manufacturing documentation (Eurobricks color-identification discussion).
2. Find the colors cataloged for that element
Use a part catalog to list the colors recorded for the exact element. This converts an unrestricted color problem into a constrained set of candidates.
Confirm that you have the right element variant. Pieces that look nearly identical from above can have different undersides, molds, or production periods. Searching the wrong design can introduce colors that were never recorded for the piece in your hand.
3. Use the set inventory when known
If the piece came from a known set, inspect that set’s inventory. The intersection of the element, set, and recorded color is generally more useful than visual judgment alone.
Inventory evidence still has limits. Rebuilt sets, mixed collections, replacement pieces, used purchases, and catalog errors can all break the assumed connection. A brick found inside a set box is not automatically original to that set.
4. Separate finish categories
Before comparing shade, classify the piece as solid, transparent, glitter, pearl, metallic, chrome, glow, opal, or another special finish.
Inspect thin edges and the underside.
5. Compare with known physical references
Place the unknown next to pieces whose identities are supported by element or set records. Use diffuse daylight or controlled neutral lighting and a white or neutral background.
Whenever possible:
- Compare identical elements.
- Clean dust and fingerprints from their surfaces.
- Align the pieces in the same direction.
- Avoid direct sun and strongly colored walls.
- Examine more than one face.
- Repeat the comparison under a second neutral light.
- Document why each reference piece is considered known.
A reference identified only from memory is not a strong reference.
6. Photograph carefully when remote help is needed
If the device allows it, fix white balance and exposure across the complete comparison. Include known-color references in the same frame rather than photographing them separately.
A useful comparison frame contains:
- The unknown piece
- Two or more labeled reference pieces
- A white or neutral background
- An optional neutral gray card
- Similar element orientations
- No color filter or portrait-mode processing
Do not crop away all context. A technically imperfect image containing known references is often more informative than an attractive close-up with no calibration clue.
7. Verify the purchasing or inventory name
Once a physical candidate has been selected, find its exact name and ID in the system you use. A BrickLink buyer should search with the BrickLink name and ID. A Rebrickable inventory should use the Rebrickable entry. Internal records can keep multiple systems in separate fields.
Do not silently translate a fan name into a marketplace listing. Preserve uncertainty when the relationship is approximate, historical, conflated, or disputed.
8. Confirm the exact element-color combination
A color can exist in a catalog without existing in the element you need. Open the part record and confirm the exact combination before ordering.
Also check whether the listing refers to:
- The correct mold or element variant
- A printed or unprinted part
- A solid or special finish
- A stickered assembly rather than a plain element
- A historical color grouped into a broader marketplace category
Troubleshooting discolored pieces
A faded, yellowed, ultraviolet-damaged, stained, or chemically altered piece may no longer match a clean reference.
When damage is suspected:
- Inspect protected surfaces underneath the piece.
- Compare several areas rather than one exposed face.
- Check whether the color remains uniform.
- Use set and production evidence to identify the plausible original color.
- Record the result as uncertain, probable original color, or discolored example.
Do not invent a catalog color to explain damage. A seller should not describe a visibly aged piece as a clean match merely because its underside resembles a reference.
Most importantly, do not make a definitive identification from one uncontrolled photograph. A photograph can eliminate candidates, but close shades require physical comparison or consistently controlled comparative evidence.
Which visual color resources are best for each task?
No single resource is best for physical comparison, historical research, cross-catalog translation, digital design, and current element availability. Use each for the task it performs well.
| Resource | Best use | Visual format | Naming systems | Filters or metadata | Important limitation |
|---|---|---|---|---|---|
| BrickLink Color Guide | Marketplace names, IDs, part-image swatches, and selected LEGO mappings | Representative part images | BrickLink with selected LEGO fields | Family, name, years, active status, standard or special | Marketplace categories and images are not physical standards |
| Rebrickable Colors | Searchable cross-references and element or set research | Photographs, renders, or generic thumbnails | Rebrickable, LEGO, LDraw, BrickLink, BrickOwl | RGB approximation, part and set records, recorded years | RGB and thumbnails may not reproduce the listed finish |
| Brick Colorstream, spreadsheet, and timeline | Physical-piece comparison and historical terminology | Consistently photographed pieces plus records | LEGO Group and BrickLink, with community research | IDs, photographs, reported production dates | Ongoing community work; use the linked specialist overview to check current availability |
| LDraw forum directory | Locating historical comparison charts | Links to charts, photographs, and tables | Multiple community systems | Thread dates and resource descriptions | Directory rather than standardized authority; some links may be obsolete |
| HEX or RGB converter workflow | Generating digital-design candidates | Input color with ranked swatches | Tool-dependent catalog names | HEX, RGB, family, or finish options | Mathematical approximation; does not guarantee element availability |
At the August 7, 2026 check, BrickLink’s guide displayed 214 colors. That is a dated database count, not a permanent statement about the size of LEGO Group’s physical palette. The same guide defines active colors as colors currently being produced by LEGO Group, but this remains BrickLink’s classification and does not establish that every element is available in each active color.
Rebrickable is especially useful when the element or originating set is known. Its table combines searchable thumbnails, digital approximations, cross-references, and inventory records. That breadth makes it a strong elimination tool, but a rendered or generic thumbnail may not depict the exact listed material.
Brick Colorstream, its associated spreadsheet, and the LEGO Color Timeline are complementary community resources. The photographs support comparison, the spreadsheet supports names and identifiers, and the timeline supports historical plausibility. Their specialist overview should be used as the access point where direct historical destinations have moved or become unavailable.
The LDraw thread is best understood as a historical directory. It began as a request for comparison charts, preferably using photographs of real example parts. Some resources were already described as unavailable or outdated when the thread was edited, and labels such as “official” in forum post titles should not be accepted without independent verification.
A HEX or RGB converter serves a different purpose. It can suggest nearby catalog colors for a rendering, reference image, or graphic design. The cited commercial workflow returns ranked candidates and advises users to make the final choice visually. Its result should still be checked for finish, physical appearance, and availability in the required element.
Prefer resources with:
- Photographs of physical pieces
- Identical or comparable example elements
- Consistent lighting and processing
- Explicit catalog-system labels
- Separate finish classifications
- Visible publication or update dates
- Element and set records
- Clear treatment of disputed or unknown mappings
A printout is a navigation aid, not a reference specimen.
From a visual match to a buildable or purchasable color
The closest-looking shade is not necessarily the most useful shade. A color can match a reference image well yet be unavailable in the element required for a model.
BrickLink defines an active color as one currently being produced by LEGO Group. That classification does not mean every element is made in it, older parts remain readily available, or a seller currently has the required quantity. These are separate questions:
- Is the color classified as active?
- Is the exact element cataloged in that color?
- Is the element available to buy in the required condition and quantity?
Before finalizing a model:
- List the elements that define its structure and visible surfaces.
- Check every required element-color combination.
- Identify acceptable substitutions.
- Separate must-match areas from flexible areas.
- Inspect marketplace listings only after the design is feasible.
- Recheck inventories before placing a large order.
A 2018 Brick Architect study illustrates the underlying availability problem. It compared 24 selected common bricks, plates, and tiles with 40 solid colors and found that none of those 24 elements was available in all 40 colors. Because the analysis used inventories and marketplace information from early 2018, it demonstrates historically uneven availability rather than current stock, rarity, or prices (2018 availability study).
The practical design principle is durable:
- Use broadly available colors for primary structures and repeated geometry.
- Use less-common colors where only a few compatible accent elements are needed.
- Verify rare or historical colors before committing an entire model to them.
- Consider the nearest workable substitute, not merely the nearest digital match.
Uncommon colors can still be effective for trim, signage, foliage, vehicles, minifigure details, and small architectural features. The problem is combinatorial: a color becomes difficult when the model needs many different element types in that color.
Before identifying, documenting, designing with, or buying a color, use this checklist:
- Correct catalog system: Is every name and number labeled as LEGO, BrickLink, Rebrickable, LDraw, BrickOwl, or a fan reference?
- Correct finish: Have solid, transparent, glitter, pearl, metallic, chrome, glow, and other finishes been separated?
- Plausible production period: Is the candidate consistent with the element or set’s recorded era?
- Exact part availability: Is the required element cataloged in that color?
- Physical confirmation: Has the piece been compared with a documented reference under neutral light?
- Documented confidence: Is the result marked confirmed, probable, possible, disputed, or unknown?
Close LEGO colors are best identified through elimination and physical comparison, not by selecting the nearest-looking web swatch. Establish the element and plausible production colors, separate finishes, compare documented pieces under neutral light, and record the final name and ID in the catalog system you actually use. The archived Isodomos Color Tree remains useful as a historical example of visual organization, but present-day identification requires dated catalogs, explicit system labels, and visible uncertainty.
Frequently asked questions
What is the most accurate way to identify a LEGO color?
Identify the exact element and determine which colors are recorded for it. If the originating set is known, use its inventory to narrow the candidates further, while allowing for substitutions or rebuilt sets.
Then compare the unknown directly with documented physical references under diffuse daylight or controlled neutral light. Use identical elements where possible, place them on a neutral background, and compare finish, lightness, hue bias, and saturation in that order. Finally, verify the chosen name and ID in the catalog used for inventory or purchasing.
Do the molded numbers on a LEGO piece identify its color?
A user-generated Eurobricks discussion indicates that molded numbers in its example represented attributes such as design, mold, and cavity position rather than a color code. That forum interpretation is useful practical evidence, but it is not official manufacturing documentation.
Use molded markings to help identify the element. Then consult cataloged element colors and, when known, the originating set inventory to produce a manageable candidate list.
Are LEGO and BrickLink color names the same?
Not consistently. Some entries share familiar wording, while others use different names and identifiers. BrickLink Very Light Bluish Gray, ID 99, for example, is mapped in BrickLink’s corresponding LEGO field to Light Stone Grey, ID 208.
Always include the system: write “BrickLink Light Bluish Gray, ID 86,” not merely “color 86.” Use BrickLink terminology when purchasing there and preserve a supported LEGO field separately when documenting cross-catalog relationships.
Can I identify a LEGO color from an RGB or HEX value?
An RGB or HEX value can generate candidates for digital design, but it cannot conclusively identify physical plastic. The value may represent a rendering convention, a photograph, or a database approximation, each with different limitations.
Different finishes can share the same database RGB value while behaving differently as physical pieces. After using a converter or color table, verify transparency, finish, hue, element availability, and appearance against known bricks.
Is the archived Isodomos Color Tree complete or current?
No. It is a historical fan-created reference preserved in a May 12, 2008 Wayback Machine capture. The available extract stops partway through the Blue family, and its palette coverage, names, and matches should not be treated as complete or current.
It remains useful for understanding one way of arranging colors into families and Dark, Basic, Medium, Light, Special, and Sand categories. The available records do not establish a connection between that archived LEGO reference and the present-day Isodomos masonry site.