Seed colour is considered as an important breeding objective.
HUH?
Ive had some WICKED crops from seeds both large and small, short and fat, black and striped (although not white), puny and GINORMOUS!!! I think (as an amatuer breeder) that the seed color, size, look, feel, etc..., is the least of my concerns. If it grows plant it. I once bred Flo2 (DJ Short - the strain has seemed to be wiped vertually clean from the web possibly to it's small yield) with Mikado x Bigbud and had a wonderfull CLONE ONLY strain (due to genetic variation/phenotypes) that were the tiniest little baby beans ever. I've also seen the reverse however. Casualties of not-so-natural-selection.
That same strain totally lost its potential once my friend and I imbred it. By then it was too late, and the origional seed was gone. last Ditch effort gone awry.