Geno: Ee/aa/W-
Pheno: White
I feel like white is one of the trickiest colors to do properly. The reason being, getting it to look accurate without being flat is super difficult and requires one to do a rather unexpected amount of subtle details.
I do this with a black base on the hooves and nose, subtle blond shades in the mane and tail, and pink countershading in the shadow areas.
This is definitely something I could improve on--I still feel the mane and tail are off slightly.