Hex to color name

Design tokens, brand guidelines, and style sheets often store colors as hex codes, yet humans still talk in names such as tomato, cornflowerblue, or rebeccapurple. This tool takes a single CSS hex value—three or six hexadecimal digits, with or without a leading hash—and returns the nearest solid CSS named color from the CSS Color Module Level 4 palette by Euclidean distance in eight-bit red-green-blue space. When the hex already matches a named color exactly, the response marks exact true and the distance is zero. When it sits between keywords, you still get a stable closest name, the keyword’s own hex and channels, and a numeric distance so design reviews and lint rules can decide how close is close enough. Invalid hex strings fail with a clear validation error instead of inventing a name.

How nearest CSS named colors are chosen

Every solid CSS named color is a fixed triple of red, green, and blue channel values from zero through two hundred fifty-five, published in the CSS Color Module Level 4 keyword table. Your input is normalized: optional leading hash, lowercased hex digits, and three-digit shorthand expanded by doubling each nibble so that f zero zero becomes f f zero zero zero zero. The algorithm then measures Euclidean distance in RGB space: the square root of the sum of squared channel differences between your color and each named triple.

The name with the smallest distance wins. When two keywords share the same RGB values—for example aqua and cyan, or fuchsia and magenta—or when two distinct triples happen to sit at the same numeric distance, the alphabetically first name is kept so the result never flips between runs. Distance zero means an exact palette hit and the exact flag is true; a positive distance means a nearest-neighbor approximation you can still use in copy, accessibility notes, or soft palette linting.

What you send and what you get back

Send one string field named hex. Accepted shapes are six-digit codes such as hash f f five seven three three, three-digit shorthand such as hash f zero zero, and the same strings without a leading hash. Spaces around the value are trimmed.

Classic checks include pure red as hash f f zero zero zero zero resolving to red with exact true; near-orange hash f f five seven three three resolving near tomato with a positive distance; and bare six-digit codes without a hash resolving the same as their hashed form.

Where hex-to-name lookup shows up in real work

Design systems and brand books often publish primary and accent colors as hex while product copy, accessibility annotations, and stakeholder slides need human-readable names for the same swatches. Front-end lint rules and CI checks can flag custom hex values that sit far from any CSS keyword when a team prefers named colors in stylesheets for readability. Data-visualization authors mapping categorical series sometimes start from hex ramps and want the closest CSS keyword for legends that must render without custom swatch images.

If you later need multi-format conversion across HEX, RGB, HSL, LAB, and CMYK, reverse conversion from names to hex only, dominant color extraction from images, or WCAG contrast checks, treat those as separate search intents and landings rather than overloading this dedicated hex-to-color-name page.