Color Sort

Reads any whitespace- or newline-separated list of hex colors (with or without leading #, 3- or 6-digit), dedupes them, and sorts the result by your chosen criterion. Near-greyscale entries (saturation under 5%) are pulled out of the hue ordering and grouped at the start, sorted by lightness, so they don't scatter randomly across the rainbow. Each row shows the swatch, the hex value, and the underlying HSL.

The greyscale rule exists because hue is undefined when there is no colour to speak of. A pure grey has no angle on the wheel, and the value a converter reports for it is an artefact of which channel happened to round highest, so sorting greys by hue interleaves them arbitrarily with the saturated colours. Pulling anything under 5% saturation into its own group at the front is a convention rather than a law, and a palette full of muted, barely-tinted colours will have entries that sit just either side of that line.

Sorting by hue puts red at both ends, because hue is an angle and the list is not. A set of reds spanning the wrap point splits into two clumps, one at each end of the output, which looks like a bug and is the flat projection of a circle. There is no ordering that avoids this; the only fix is to know where your palette starts.

Deduplication is exact and works on the parsed value, so #FFF, #ffffff and #FFFFFF collapse to one entry. Colours that merely look identical do not: two hex values a single step apart are different entries even though no screen will show a difference between them. If you are trying to find visually redundant colours in a palette, a perceptual distance measure is the right instrument.

The sort is on sRGB values as written, with no colour management. A palette authored in a wider gamut will sort by the numbers it was written with rather than by how it renders.