MIT Licensed .Net library intended to make working with colors easy.
You can do stuff like easily convert between colors spaces like Rgb, Hsl, Xyz, Yyz, Cmy, Cmyk, and CIE*Lab. More spaces supported soon!
var startingRgb = new Rgb { R = 149, G = 13, B = 12 }
var cmy = startingColor.To<Cmy>();
Online example at http://colormine.org/color-converter
You can also calculate delta-e, it's currently a bit awkward but undergoing rapid development. More algorithms coming soon!
CIE76 http://colormine.org/delta-e-calculator/
var deltaE = startingRgb.Compare(cmy,new Cie1976Comparison());
CMC l:C http://colormine.org/delta-e-calculator/cmc
var deltaE = startingRgb.Compare(cmy,new CmcComparison(lightness: 2, chroma: 1));