You can't make a new color because whatever you cross it will be a hybrid and still carry the genes of the two birds it came from. This means you will get mixed offsprings. So there is no way to get a new color because it will be a hybrid.
People actually get a degree in this. You would have to be an AI whizz and you would have to know your genes very well. It is a very touchy process. I have only attempted to AI a few times and that was to create a bob-bird.
Blonde, Silver, White, Jumbo Wisconsin, Indiana Giant, Tennessee Red, and Mexican Speckled. Be careful with AI if you use two lethal genes it could either kill the eggs or the chicks could die after they hatch.