Image Hex Color Mapper

Map every pixel in an image to its nearest named CSS color or hex value.

Tested tool guide Tested browser tools Checked August 16, 2026

What Image Hex Color Mapper does and how it behaves

Image Hex Color Mapper answers a per-pixel question: which CSS color name or hexadecimal RGB value best represents each point in an image? It treats the source as a grid of individual colors and expresses every pixel in the requested form, rather than returning only one dominant swatch or a short palette. The common surprise is that CSS color names form a limited set. Most photographic colors have no exact named equivalent, so named output necessarily approximates them, often assigning one label to several distinct source colors.

How the result is produced

Per-pixel mapping

The source image is considered a rectangular pixel grid. For every location, the mapper associates the source color with an output color value, so neighboring pixels remain separate decisions. It does not reduce the image to an average or a frequency-ranked palette. This distinction matters for antialiased edges, gradients, and tiny raster icons, where many nearby pixels can carry slightly different channel values.

Names and hex values

CSS-name mapping selects from the standardized named-color vocabulary. A source RGB value that is not in that vocabulary must therefore receive an approximation. Hexadecimal notation instead writes numeric channels, commonly as #RRGGBB, where each two-digit pair describes red, green, or blue. The name is not always a unique identifier: CSS includes aliases such as aqua and cyan, and gray and grey, whose paired names represent identical colors.

Good uses

Converting a pixel-art icon or sprite into a coordinate-by-coordinate list of CSS-friendly color labels before rebuilding the asset in code.
Checking how a raster brand mockup would collapse into the CSS named-color vocabulary, including where distinct shades are mapped to the same name.
Reading hexadecimal color assignments across a small flat-color image when manually sampling each pixel with an eyedropper would be slow and easy to misalign.

Limits and checks

Nearest is not self-defining. The chosen label can depend on the color space and distance rule used for comparison. If the mapper does not state that rule in its result, do not interpret the winner as an objective perceptual judgment.
CSS aliases can make a name look arbitrary. Aqua and cyan share one defined color, as do fuchsia and magenta and the gray/grey spellings. A different alias would not mean a different RGB result.
Do not assume transparency is preserved in a six-digit hex value. #RRGGBB describes red, green, and blue but carries no alpha component. Transparent or semitransparent pixels need separate attention, especially if the displayed result has been composited against a background.

Common questions

Will mapping to CSS color names reproduce the source exactly?

Not in general. Exact reproduction is possible only when every relevant pixel already matches the color represented by the returned name and any transparency is handled compatibly. Photographs, gradients, shadows, and antialiased edges normally contain many colors outside the named set. For those pixels, a nearest-name result deliberately changes the numeric color, even if the visual difference is small.

Does the mapper upload the image?

No. The Image Hex Color Mapper runs entirely in the browser, so the image is processed locally and is not uploaded by this tool. This is relevant for unpublished screenshots, sprites, and design assets. Exporting, copying, or otherwise sharing the mapped result is a separate user action and should be evaluated according to where that result is sent.

References and verification

The behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.