ColorDistance

ColorDistance[c1, c2] gives the approximate perceptual distance between color directives c1 and c2.

ColorDistance[list, c] gives color distances between elements of list and c.

ColorDistance[image, c] gives an image whose pixel values are color distances from pixels to color c.

Examples

Distance between two colors:

ColorDistance[Red, Orange]
(* 0.344315 *)

Distance between Red and Blue:

ColorDistance[Red, Blue]
(* 0.764716 *)

Please visit the official Wolfram Language Reference for more details.