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Paste any hex code and get the closest of all 148 CSS color names, matched by how colors actually look. See RGB, HSL, OKLCH, and contrast at a glance, or name a whole palette at once.
Need to convert or create colors? Try the Color Code Generator or the Color Palette Generator.
Last updated: October 5, 2026 · Published: 2026-04-09 · Updated: 2026-10-05
Accepts #RGB, #RGBA, #RRGGBB, #RRGGBBAA (with or without #), rgb(), hsl(), three numbers like 30, 144, 255, or any of the 148 CSS color names.
#3498DB
Dodger Blue
vivid blue
Similar
#3498DB is closest to Dodger Blue (dodgerblue), #1E90FF, at ΔE00 5.76.
5 closest CSS color names
Names are matched with the CIEDE2000 color difference (ΔE00) against all 148 CSS named colors, so every name can be pasted into CSS as is. Alpha is kept in the values but ignored for matching. Everything runs in your browser.
A hex code to color name tool tells you what to call a color written in hexadecimal. There are 16,777,216 six-digit hex colors but only 139 distinct CSS named colors, so most hex codes don't have a name of their own. The tool finds the named color that looks closest.
For example, #3498DB is closest to Dodger Blue (#1E90FF), a vivid blue, at ΔE00 5.76. The match uses CIEDE2000, the CIE's formula for how different two colors look, and every name it returns is a valid CSS keyword.
Paste a color
Enter a hex code, rgb(), hsl(), three numbers, or a color name, or pick a color with the color picker.
Read the closest name
The tool compares your color with all 148 CSS named colors using CIEDE2000 and shows the 5 closest, with how close each one is.
Copy what you need
Copy the CSS name, HEX, RGB, HSL, or OKLCH value, or a one-line summary. Switch to list mode to name a whole palette.
Ten common UI colors, matched with CIEDE2000. The last column shows what plain RGB distance would pick instead. The two methods disagree on 3 of them.
| HEX | Closest CSS name | ΔE00 | Match | Described as | RGB distance picks |
|---|---|---|---|---|---|
| #3498DB | Dodger Blue #1E90FF | 5.76 | Similar | vivid blue | Same |
| #E67E22 | Peru #CD853F | 6.08 | Similar | vivid orange | Chocolate |
| #2ECC71 | Medium Sea Green #3CB371 | 7.27 | Similar | muted green | Same |
| #C0392B | Fire Brick #B22222 | 5.33 | Similar | muted red | Same |
| #8E44AD | Dark Orchid #9932CC | 5.42 | Similar | muted purple | Same |
| #F1C40F | Gold #FFD700 | 4.77 | Close | vivid yellow | Same |
| #1ABC9C | Medium Aquamarine #66CDAA | 6.50 | Similar | vivid cyan | Light Sea Green |
| #2C3E50 | Dark Slate Blue #483D8B | 11.43 | Loose match | dark grayish blue | Dark Slate Gray / Dark Slate Grey |
| #FF5733 | Tomato #FF6347 | 3.13 | Close | vivid red | Same |
| #ECF0F1 | White Smoke #F5F5F5 | 2.23 | Close | near white | Same |
Your color is converted from sRGB to CIELAB, a color space built so that distances roughly follow what people see. It is then compared with every CSS named color using CIEDE2000, which adds corrections for lightness, chroma, and hue, especially in blues. The named color with the smallest difference wins.
The implementation is checked against all 34 test pairs published by Sharma, Wu, and Dalal in 2005.
The match label is a plain-language band this tool puts on the ΔE00 number:
| Label | ΔE00 |
|---|---|
| Exact match | 0 |
| Very close | above 0 to under 2 |
| Close | 2 to under 5 |
| Similar | 5 to under 10 |
| Loose match | 10 or more |
Every one of these reads as the same blue.
| You paste | Read as | Closest name | ΔE00 |
|---|---|---|---|
| 1e90ff | #1E90FF | Dodger Blue | 0 |
| #1E90FF | #1E90FF | Dodger Blue | 0 |
| rgb(30, 144, 255) | #1E90FF | Dodger Blue | 0 |
| hsl(210 100% 56%) | #1F8FFF | Dodger Blue | 0.38 |
| 30, 144, 255 | #1E90FF | Dodger Blue | 0 |
| Dodger Blue | #1E90FF | Dodger Blue | 0 |
CSS hex colors use 3, 4, 6, or 8 hexadecimal digits, and letter case doesn't matter. Short forms double each digit, and the fourth or last pair sets alpha, from 00 for fully transparent to FF for fully opaque.
| Notation | Example | Full form | As rgb() |
|---|---|---|---|
| #RGB | #09F | #0099FF | rgb(0 153 255) |
| #RGBA | #09F8 | #0099FF88 | rgb(0 153 255 / 0.53) |
| #RRGGBB | #0099FF | #0099FF | rgb(0 153 255) |
| #RRGGBBAA | #0099FF80 | #0099FF80 | rgb(0 153 255 / 0.5) |
The full list from CSS Color Module Level 4, grouped by hue and sorted light to dark. Pairs like gray and grey share one swatch, so 148 names make 139 swatches.
Sixteen names come from the VGA palette, by way of HTML. Most of the rest come from the X11 color list used on Unix systems, which SVG and then CSS adopted.
| The 16 basic colors | HEX | RGB |
|---|---|---|
| black | #000000 | rgb(0 0 0) |
| silver | #C0C0C0 | rgb(192 192 192) |
| gray | #808080 | rgb(128 128 128) |
| white | #FFFFFF | rgb(255 255 255) |
| maroon | #800000 | rgb(128 0 0) |
| red | #FF0000 | rgb(255 0 0) |
| purple | #800080 | rgb(128 0 128) |
| fuchsia | #FF00FF | rgb(255 0 255) |
| green | #008000 | rgb(0 128 0) |
| lime | #00FF00 | rgb(0 255 0) |
| olive | #808000 | rgb(128 128 0) |
| yellow | #FFFF00 | rgb(255 255 0) |
| navy | #000080 | rgb(0 0 128) |
| blue | #0000FF | rgb(0 0 255) |
| teal | #008080 | rgb(0 128 128) |
| aqua | #00FFFF | rgb(0 255 255) |
Where an HTML name already existed, CSS kept the HTML value. So these four mean different colors in X11 and in CSS, and X11's green is CSS lime.
| Name | In CSS | In X11 |
|---|---|---|
| gray | #808080 | #BEBEBE |
| green | #008000 | #00FF00 |
| maroon | #800000 | #B03060 |
| purple | #800080 | #A020F0 |
"These color names are standardized here, not because they are good, but because their use and implementation has been widespread for decades and the standard needs to reflect reality." — CSS Color Module Level 4
The tool shows each color's contrast ratio against white and black. WCAG asks for at least 4.5:1 for normal text and 3:1 for large text at level AA, and 7:1 for normal text at level AAA.
#3498DB reaches 3.15:1 on white (AA large text only) and 6.66:1 on black (AA), so black text reads better on it.
| Year | Event |
|---|---|
| 1976 | The CIE defines the CIELAB color space, which CIEDE2000 and this tool use to compare colors. |
| 1985 | Jim Gettys checks the first X Window System color list, rgb.txt, into version control. |
| 1986 | The list ships with X10 release 3 on June 7, tuned for DEC VT240 terminals. |
| 1989 | X11R4 ships the list close to its current form, with colors from Paul Raveling based on Sinclair Paints samples and from John C. Thomas based on a box of 72 Crayola crayons. |
| 2001 | The CIE publishes the CIEDE2000 color-difference formula in CIE Publication 142-2001. |
| 2005 | Gaurav Sharma, Wencheng Wu, and Edul Dalal publish implementation notes and test data for CIEDE2000, used to verify this tool. |
| 2014 | rebeccapurple (#663399) joins CSS Color Level 4 in June as a tribute to Eric Meyer's daughter, becoming the 148th named color. |
| 2020 | Björn Ottosson publishes the Oklab color space, the basis of the oklch() values shown by this tool. |
Finding a color's name, CIEDE2000, CSS named colors, input formats, contrast, and naming whole palettes.
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