Inbreeding does not 'create' faults as such, it simply brings the 'rubbish into view', so to speak. The traits exist, they are simply hidden. The reoccurance of certain genes [which is more likely in related animals, as they are more likely to have similar genetics] will make the traits manifest. Which is fine if you are willing to cull extremely hard to remove the deleterious traits, so that only the desired traits remain...but honestly, to do that just for colour is ridiculous.
Now if it was some trait that gave an animal a distinct working or health advantage...
Outcrossing on the other