Turtle Creek Farms is not standing a stallion. However we do endorse stallions we prefer to breed with our mares. Here is a basic color chart if you want to dream about the color of your next foal. I like this chart because of the graphics.
If you know specifics like dilutions and modifiers, whether the horse is homozygous or heterozygous, etc - you will be able to refine your search to determine a more accurate result.