If you're talking about For Goodness Snakes line, he explains them in some of his Youtube videos. They're from a very gold Normal (I think) to a Mojave, then just bred back into each other. I believe he said the normals from the Gold Blush Mojaves are always a bit more gold than 'normal'

They're what he is known for (and his massive Big Mama BP), so he does make frequent videos on them.