So in certain dogs, we have two different allele pairs at two different low side that ultimately determine the expression of some particular color trait, the code color trait. So to designate these different types of allele pairs, we're going to use the letter D to designate one allele pair and the letter B to designate the second allele pair. So let's begin by supposing that we have a dog that is homozygous dominant. So let's suppose our dog is homozygous dominant for our D gene. And so we have uppercase D, uppercase D. In this particular case, what happens is we're going to have a dark coat color, but there are two possibilities. We can either have a light brown color, so a chocolate color, or we can have a black color.