clr

clr is a go library to manage different color spaces, convert between them and compare colors.

clr currently supports sRGB HSV, and Hex types, with conversions to sRGB, Hex, HSV, HSL, CMYK, XYZ and CIE-Lab for each.

Comparisons are done in CIE-Lab using Delta E*. I may add more comparison options in the future, but for now Delta E* performs well enough.

Given a mapping from Hex to color names you can find the nearest color visually in the mapping from any given color. Data for these mappings is up to you to provide by implementing ColorTable.

There is also a CLI tool to explore the package called clr.

$ clr --hex "#0c6624"
&{Code:0c6624}
sRGB: 12 102 36
HSL: 136 78 22
HSV: 136 88 40
CMYK: 88 0 64 60
HEX: 0c6624
Generic Color: Green
Specific Color: Camarone

API

clr is based on two primitives Color and ColorTable. Color has three backing types currently, Hex, RGB, and HSV. You can add your own types by implementing the Color interface.

type Color interface {
	Valid() bool
	RGB() (int, int, int)
	HSL() (int, int, int)
	HSV() (int, int, int)
	CMYK() (int, int, int, int)
	XYZ() (float64, float64, float64)
	CIELAB() (l, a, b float64)
	Hex() string
	ColorName(colors ColorTable) ColorSpace
	Distance(c Color) float64
	RGBA() (r, g, b, a uint32)
}

clr also contains functionality for finding the closest color name to a given color. This requires an instance of ColorTable, which provides the possible color matches. clr matches to the closest color in CIELAB.

type ColorTable interface {
	Iterate() []Color
	Lookup(hexCode string) ColorSpace
}