The lessons from scratchapixel.com were for me the most helpful, they really made all the stuff about colour-spaces "click" for the first time. Mainly this chapter, explaining about the tristimulus, CIExyz and how they transform into sRGB and what is up with that horseshoe shape:
Further, if you click around there's a few more chapters relevant to colours that put this theory into practice (in the context of raytracing and rendering):
http://www.scratchapixel.com/lessons/3d-basic-lessons/lesson...
Further, if you click around there's a few more chapters relevant to colours that put this theory into practice (in the context of raytracing and rendering):
http://www.scratchapixel.com/lessons/3d-advanced-lessons/bla...
http://www.scratchapixel.com/lessons/3d-advanced-lessons/sim...