A while ago I ported this code from GSkinner.com and forgot to share it. It provides a way to adjust Brightness, Contrast, Saturation and Hue based on a range of numeric values as well as multiply matrices, and works in conjunction with the ColorMatrixFilter. I hope this helps someone!
Also to note, there was a similar tool called ColorMatrixHelper hinted at a couple years ago but I’m not sure the code ever became public. @Matse – any comment on that?