Color Database Methodology

Our Color Names Browser contains over 7,000 named colors compiled from seven independent color naming systems. This page documents how the database was built, how colors are classified, and how the canonical name for each color is selected.

The Seven Source Systems

Each source system contributes color names from a different domain — web standards, scientific classification, operating systems, paint manufacturing, crowdsourced surveys, cultural products, and community curation. Together, they provide the most comprehensive named color reference available.

1. CSS3 Named Colors (148 colors)

The W3C CSS Color Module Level 3 defines 148 named colors that all browsers recognize. These include the original 16 HTML color names (aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, yellow) plus 132 extended names adopted from the X11 color list. CSS3 names are an open W3C standard with no restrictions.

2. ISCC-NBS System (267 categories)

The Inter-Society Color Council and the US National Bureau of Standards published the ISCC-NBS Method of Designating Colors in 1955. It classifies colors into 267 non-overlapping descriptive categories based on the Munsell color solid — categories like "vivid red," "light blue," "dark yellowish green," and "pale yellow." The system was published by the US government and is in the public domain. We use the 267 centroid colors (digital conversion by Voluntocracy, 2003) as the organizational backbone of our database.

3. X11 Color Names (455 colors)

The X Window System, used by Unix-like operating systems, defines approximately 455 color names in its rgb.txt file. These names predate the web and are the ancestor of CSS named colors. X11 color names are MIT licensed.

4. Crayola Crayon Colors (120 colors)

Crayola has named over 120 crayon colors since 1903, many of which have become culturally familiar — "burnt sienna," "cerulean," "macaroni and cheese." Crayola is a registered trademark of Crayola LLC. Color names are referenced for identification purposes only and do not imply endorsement or affiliation.

5. Resene Paint Colors (1,379 colors)

Resene is a New Zealand paint company whose color naming system is widely used for its practical, real-world naming. The Resene color list is copyright Resene Paints Ltd (2001) and is used under license. Permission is granted for any purpose, with the condition that the "Resene" prefix is removed from display names. Our pipeline strips this prefix automatically.

6. XKCD Color Survey (954 colors)

In 2010, Randall Munroe (xkcd.com) conducted a crowdsourced color naming survey with 222,500 participants. Participants were shown colors and asked to name them, producing 954 named colors with colloquial, natural-language names like "blurple," "poison green," and "baby poop green." The survey data is released under CC0 (public domain dedication), as stated in the file header at xkcd.com/color/rgb/.

7. meodai Community Collection

The meodai/color-names project on GitHub is a community-curated color name database maintained by David Aerne, licensed under the MIT License. It aggregates color names from thousands of contributors, including brands, products, and natural phenomena.

How Colors Are Classified

ISCC-NBS Classification

Every color in the database is classified to its nearest ISCC-NBS centroid using CIE Delta E 1976 perceptual distance. This means we compute the CIE L*a*b* coordinates of each color and find the closest of the 267 ISCC-NBS centroid colors. The resulting category name (e.g., "vivid red" or "light blue") provides a scientifically grounded description of the color's appearance.

Hue Family Assignment

Each color is assigned to one of 14 hue families based on its HSL values: Red, Red-Orange, Orange, Yellow-Orange, Yellow, Yellow-Green, Green, Blue-Green, Blue, Blue-Purple, Purple, Red-Purple, Brown, and Olive. Brown and Olive are included as extended families because they represent perceptually distinct categories for low-saturation, mid-lightness warm colors. Colors with very low saturation are classified as White, Black, or Gray depending on lightness.

Quality Tiers

Each color is assigned a quality tier based on its source:

• Standard — Colors from CSS3, ISCC-NBS, or X11. These are the most widely recognized and authoritative names.
• Named — Colors from Resene, XKCD, or Crayola. These are well-known but less formal than standard names.
• Community — Colors from the meodai collection. These are community-curated and may include brand or product names.

Canonical Name Selection

Many colors appear in multiple source systems. For example, the hex code #FF0000 is named "Red" in CSS3, X11, and ISCC-NBS. When multiple names exist for the same color, we select a canonical name using source priority:

1. CSS3 (highest priority)
2. ISCC-NBS
3. X11
4. Crayola
5. Resene
6. XKCD
7. meodai (lowest priority)

When two names from the same priority source exist, the shorter name is preferred. All alternative names are preserved as aliases and can be found via search.

Per-Color Data Fields

Each color entry in the database includes:

• Hex, RGB, HSL, HSV — standard color space representations
• CIE L*a*b* — perceptual color space used for Delta E matching
• OKLCH — modern perceptual color space (L = lightness, C = chroma, H = hue)
• ISCC-NBS category — scientific classification (e.g., "vivid red")
• ISCC-NBS Delta E — distance to the nearest centroid
• Hue family — one of 14 perceptual families
• WCAG contrast ratios — against white and black, for accessibility checking
• Sources — which naming systems recognize this color
• Tier — quality classification (standard, named, or community)
• Aliases — alternative names from other sources

Copyright and Licensing

Individual color names are factual designations (short phrases and data points) and are not subject to copyright protection under US law (17 U.S.C. § 102(b); Feist Publications v. Rural Telephone Service Co., 499 U.S. 340). The compilation of these names into a unified, classified database is copyright graf1x.com.

Source data is used under the following terms:

• CSS3, ISCC-NBS, X11 — open standards / public domain, no restrictions
• XKCD — CC0 (public domain dedication)
• Crayola — trademark referenced for identification only, no endorsement implied
• Resene — used under license, "Resene" prefix removed per terms
• meodai — MIT License