The pigmentation in the skin is used by the fetus as a map of where to put the organs & nerves Thats why certain white patterns cause partial or minor things like blindness or deafness where as things that are completely white don't have any map Lethal white foals when born often don't live because their organs are either wrong and or incomplete
It really is fascinating. Recently I've been wanting to do more research into how the lethal white gene works and how lavender works (forgot the actual name of that gene)
I started studying color one day when I was laid up sick for a few weeks That was 7 yrs ago I find the subject fascinating The most color genetic study has gone into rabbits & horses There are parallels between all mammals
@Tahiri Recessive is when one gene hides behind another or doesn't show of there is a single copy of the gene The capital letters mean they have it all lowercase means they do not have it prlprl is no Pearl gene therfore causing a pearl horse