How come Flat Coats don't come in yellow?

I was just wondering, you know like a lab? they come in two of the colors, why not three? Maybe because Goldens and Flat Coats would get mixed up.

Actually, Flat coateds DO come in yellow. However it is a disqualifying fault and comes with health problems, so they aren't commonly bred. They are fairly rare too. I'll see if I can find any pics...

You can get livers as well.

Well, I've seen a liver at a dog show, it's the same color as a cocolate lab. They come in Liver and Black, I didn't know that they could come in yellow? That's cool! yeah pics please! I have a black one, you know the whole breed is pretty rare itself. :)