You get specific mutations by breeding parent birds who have the genes for that mutation. It's not like mixing paint, where you can combine yellow and blue to get green. If you want whiteface for example, both parents need to have the whiteface gene. They can be visual whiteface (meaning that they have two copies of the gene) or they can be split (meaning that they are not whiteface themselves but they are carrying the gene and can pass it to their offspring).
There are special rules for sex-linked mutations (lutino, pearl, cinnamon). If the father has the gene (either visual or split), that's enough to get daughters who are visual for the mutation. To get sons who are visual, you need a father who has the gene plus a mother who is visual for the mutation.