Color Name Finder
Find the nearest CSS named color for any HEX or RGB value.
Best match
royalblue
#4169E1
Other close matches
What are CSS named colors?
CSS supports 148 predefined color keywords — from aliceblue to yellowgreen — that you can use directly in stylesheets without a HEX or RGB value. They are defined by the W3C and supported in every modern browser. This tool finds which named color is closest to any arbitrary color you enter, ranked by Euclidean distance in RGB space.
How similarity is calculated
The distance between two colors is computed as the straight-line distance in RGB space: √((R₁−R₂)² + (G₁−G₂)² + (B₁−B₂)²). The maximum possible distance is about 441 (black to white), so similarity is shown as 100 − (distance / 441 × 100). A score of 100% means the color is an exact match. This method is fast and works well for most use cases, though perceptually uniform spaces like OKLAB give slightly more accurate human judgements.
Frequently asked questions
Why does my color show a low similarity score?
CSS named colors were chosen for human readability, not coverage of the full color space. Many highly saturated or mid-range colors have no close named equivalent. A score below 85% means the nearest named color is visually quite different — in those cases, using a HEX or RGB value in your CSS is the right choice.
Are grey and gray both included?
CSS defines both spellings as aliases for the same value. This tool uses the gray spelling for all gray-family colors to avoid duplicates in the results list.
