I made my own implementation of this a while ago as well. One thing to keep in mind though is that the human eye doesn't perceive all colors uniformly. This mea

I made my own implementation of this a while ago as well. One thing to keep in mind though is that the human eye doesn't perceive all colors uniformly. This means you can't treat the R,G,B spectrum as a 3-dimensional space, as the distance between two points in this space doesn't take the characteristics of the human eye into account. The solution to this is to convert your RGB colors to the CIELab color space (http://en.wikipedia.org/wiki/Lab_color_space http://en.wikipedia.org/wiki/Lab_color_space) and use the Lab values for your 3-dimensional space.