Colour experts, help educate me?

I had posted a while ago about what colour my foal is likely to be, and everyone said that because we don't know much about the mare's genetics it's hard to tell. We still don't know anything about the stud, but have been told he's a purebred black friesian (although just watch, I'm going to wind up with a 12hh paint pony!).

I still don't know much about her genetics, but I did find her pedigree with some information on the colours in her family.

Rockin T Lee Red Quarter Horse

Can you tell anything about her agouti status or anything else from this? If so, if you could write down your train of though, that would be awesome! I find this really interesting and I'm trying to learn more about it.

Thanks!

Cant give you any idea on an agouti status as agouti hides on the red base. There is no way to know without testing.

Ah, okay.. I didn't know that it hides.. Thanks :)

Agouti, which causes bay, brown and wild bay, only affects black hairs. If a horses is red, it can still carry the agouti genes but they would not be visibly present as they do not affect the red hairs.

And breeding to a Friesian doesn't guarantee a black horse as not all Friesians are homozygous for black and even within purebred Friesians, a chestnut can be produced. They are rare and aren't desired, but do happen.

Yes, I knew about the fox friesians, but just for the sake of simplicity it seems easier to assume that the stud's homozygous black.

NdAppy, what does wild bay mean? Forgive my ignorance :)

Well you know how a "normal" bay has high black on it's legs? On a wild bay that black is restricted even farther down the legs, sometimes coming no higher than the fetlocks.

It's a different form of bay. Instead of having black points that go all the way up to the knees and hocks, it only comes up to about the pastern. Like this picture:

That's interesting, I'd never seen that before. Is that something that would be carried genetically, or is it like markings that are pretty random?

It's a gene. It's the A+ form of Agouti. Normal bay is the A form and At causes brown.