W3C CSS Extended Color Dictionary

Color Name Finder

Identify the name of any color. Enter a HEX or RGB code to discover its closest official CSS color keyword, visual match score, and alternative design shades.

HEX Color Code

RGB: (59, 130, 246)

Your Color

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Named Match

🎯 93% Visual Match

DodgerBlue

Category: Blue · Standard CSS Color Name

Closest Alternative Named Colors

RoyalBlue

#4169E1

91.9%

CornflowerBlue

#6495ED

90.3%

SteelBlue

#4682B4

85.5%

MediumPurple

#9370DB

80.7%

DeepSkyBlue

#00BFFF

80.4%

CadetBlue

#5F9EA0

78.9%

How Color Matching & CSS Named Colors Work

The History of Web & CSS Color Keywords

In HTML 3.2 and early web standards, browsers supported only 16 VGA colors (such as silver, maroon, and teal).

With the adoption of the X11 color specification in CSS3 and CSS Color Module Level 4, the list expanded to 148 standard keywords. These include whimsical names like PapayaWhip, CornflowerBlue, and the historic RebeccaPurple (added in honor of web pioneer Eric Meyer's daughter).

Perceptual Distance: Why Simple RGB Euclidean Distance Fails

A naive approach computes Euclidean distance: sqrt((R1-R2)² + (G1-G2)² + (B1-B2)²). However, the human visual system possesses significantly higher sensitivity to green wavelengths than red or blue.

Our finder applies the Redmean weighted perceptual formula, adapting RGB coordinates according to average red luminance to closely approximate CIELAB ΔE (Delta-E) perceptual distances without requiring expensive color space conversions.