No, I've never picked a horse because of color. I like a great many colors. Certainly some I like better than others, but it's a bit like saying I'm going to pick out my girlfriend based on the color of her hair. Color would have had me buying my older mare's kid brother (who was a beautiful animal with a black brown and white pattern, all three colors in his tail) instead of my mares cousin. He did make my short list of 5, but there were 3 fillies ahead of him so he would have been hard pressed to beat all three (especially the filly I did pick). There was nothing wrong with him (he would have been an excellent choice) and color would have given him a lead the others couldn't have matched.
Now there are colors I prefer and some I'm not so fond of. The first horse I owned (mine, not someone else in the family's horse) was probably the least attractive horse I've ever had (white, not grey, pink skin, blue eyes). To me she was beautiful (but that's the blind love of a 14 year old boy finally getting his own horse). She did turn out to be on the best horses I've ever owned. Best working horse for cattle in the family. But today I probably would have passed on her unless there was nothing else equal to her in the things that matter.
I won't say colors can't play a part in what I would buy. There are colors I will not buy. I won't buy any horse that's pastel blue, Kelly Green and I'd recommend everyone avoid any that are hot neon pink.