Color Name Lookup

Paste a hex colour — #3b5998, rebeccapurple, anything in the CSS set — and see the closest matching CSS named colour. Distance is measured in CIE Lab using the CIE76 ΔE formula, so a smaller number is a closer perceptual match. Click any swatch in the palette to load it. Pure client-side, no upload.

Input — hex, rgb(), hsl(), hwb(), or a named colour

Clear

Accepts #RGB, #RGBA, #RRGGBB, #RRGGBBAA, rgb(), hsl(), hwb(), or any of 148 named CSS colours. Alpha values are composited over white before lookup.

CSS named-colour palette — 148 colours

How the match is computed

• Each CSS named colour has a fixed sRGB value. We pre-compute its CIE Lab coordinates once at startup.
• Your input is parsed, composited over white if it has alpha < 1, and converted to Lab.
• Distance is the CIE76 formula: ΔE = √((ΔL)² + (Δa)² + (Δb)²). Smaller is closer.
• Verdicts: ΔE < 1 → exact match, < 2.3 → imperceptible, < 10 → only an expert would notice, < 25 → similar, otherwise far.
• The CSS named set is sparse — many real-world hexes have no close neighbour. A "far" verdict is the honest answer in that case.
• Nothing leaves the browser. The lookup runs against a static, embedded list of 148 named colours.