I for the most part breed zebra finches. However I do breed a few parrotlet mutations and canaries. To me the zebra finch has always been very interesting there are so many mutations, and color combinations that one can breed for it just depends on the breeder and what it is they are trying to achieve. For example there are breeders that breed strictly for size and confirmation and leave color out of the equation. There are also breeders that breed for color. What it is you want to achieve and what color combinations you would like to see in your aviary is totally up to each breeder.
There are just so many mutations and colors that it makes the Zebra Finch a very interesting bird to breed.