nope, egg color has nada to do with genetics in BQs. Atleast not this far in the research that's been done on them.
If I ever find any new info I'll deffinatly letcha know about it!
When I first got into bqs, i thought like you taht they must be genetic since theres so many differences in colors but nope that's not the case...it's the layers in the hens eggs and the duration in which they're let to develop that determines the color.
by the way, you could think that about coturnix quail too, since coturnix quail can come in speckled, pure white, brown etc.
Even chicken eggs from purebreds can come in light and dark colors.
OH and another thing to add, My wild pied, and my cinnamon both hatched out of green eggs....that's two totally different colors to give you an idea.