So their eyes are blue and they're true breed for that color. And we take a female who is also true breed for that blue eye color. Now, if they mate, they will produce an offspring who also has the color blue. And no matter how many times we try to mate them, we will always get that same result. So that is what we mean by a true breeding plan. A true breeding plan for any one of these trades listed below will produce only that trade generation after generation.