Here some implementations in Matlab code and some general color image processing functions.
Color Feature Description: matlab and C code for discriminative color descriptor, color naming (2 versions) and the hue and opponent color descriptor.
Color Feature Description (old) : matlab code for the hue and opponent color descriptor.
Color Constancy: matlab code for weighted Grey-Edge color constancy algorithm.
Color Attention : example code in matlab to implement color attention.
Object Recoloring : matlab code for object recoloring including a gui.
Color Feature Detection I : some color image processing functions, including color edge detection, photometric invariant, color Canny edge detection, Harris point detection, and color boosting.
Color Feature Detection II : implementations of color Harris, color Laplacian feature detection.
Color Constancy: matlab code for edge-based color constancy. The file also includes implementations of Grey-World, max-RGB and Shades of Grey.
Top-Down Color Constancy : matlab code for computation of color constancy based on the semantic lieklihood of the image (ICCV 2007).
Color Naming: matlab code and color name assignment data for color naming.