About the Color Name Finder
This color name finder answers "what is this color called?" for any HEX, RGB or HSL code. It compares your color with all 148 standard CSS named colors — the names every browser understands, from AliceBlue to YellowGreen — and returns the nearest one, the exact code of that named color, how far apart they are and a plain-English color family such as "dark blue" or "light gray".
It is useful for writing alt text and design documentation, naming variables and design tokens, describing a brand color to a client, or simply settling an argument about whether something is teal or turquoise. A table lists the eight closest named colors so you can pick the name that fits best.
Closeness is measured in the OKLab perceptual color space, which matches human judgement of similarity much better than comparing raw RGB numbers. A distance under about 2 means the two colors look practically identical; above 10 the name is only a loose description.
How to use the color name finder
- 1Paste or type a HEX, rgb() or hsl() color.
- 2Read the nearest CSS color name and its exact HEX code.
- 3Check the difference and match quality to see how close the name is.
- 4Browse the table of the eight nearest names for alternatives.
Formula and method
Your color and each of the 148 CSS named colors (CSS Color Module Level 4) are converted from sRGB to the OKLab perceptual color space: channels are linearised, mixed into cone-like responses, cube-rooted and combined into lightness L and the opponent axes a (green–red) and b (blue–yellow). The named color with the smallest Euclidean distance is the match; the distance is scaled by 100 and reported as ΔE.
Gray/grey spellings and the identical pairs aqua/cyan and fuchsia/magenta are merged. The color family is a simple rule on the HSL hue angle, saturation and lightness (e.g. hue 195–255° is blue, lightness under 30% adds "dark").
- L
- OKLab lightness (0 = black, 1 = white)
- a, b
- OKLab green–red and blue–yellow axes
- ΔE
- Perceptual difference × 100 (≈2 just noticeable)
Worked examples
Mid blue #3A7BD5
#3A7BD5 is a medium, fairly saturated blue. Of the CSS names, Royal Blue (#4169E1) is perceptually nearest at 5.15 ΔE — close, but visibly different — with Steel Blue (5.94) and Dodger Blue (7.64) as runners-up.
Exact named color rgb(255, 99, 71)
rgb(255, 99, 71) is #FF6347, which is exactly the CSS color tomato, so the difference is 0.
Is #008B8B teal or turquoise?
#008B8B is exactly the CSS named color darkcyan. Teal (#008080) is very close but slightly darker, while turquoise (#40E0D0) is much lighter.
Frequently asked questions
How many named colors are there in CSS?+
CSS Color Level 4 defines 148 named color keywords, including duplicate spellings such as gray/grey and identical pairs such as aqua/cyan and fuchsia/magenta. All of them work in every modern browser, for example color: rebeccapurple.
Why not just compare RGB values?+
Equal steps in RGB do not look equal to the eye — a change in green is far more noticeable than the same change in blue. OKLab is designed so that distances match perceived differences, which makes the "nearest" name much more reliable.
Can I use the color name instead of the HEX code?+
Only if the match is exact or practically identical (ΔE under about 2). Otherwise the named color is visibly different, so keep the HEX code in your CSS and use the name only as a description.
What is the difference between teal, cyan and turquoise?+
In CSS, cyan (#00FFFF) is the pure, bright blue-green; teal (#008080) is a dark, half-strength cyan; turquoise (#40E0D0) is a lighter green-leaning cyan; and darkcyan (#008B8B) sits just above teal.