Odd colors and patterns

I am a huge fan of odd animal markings and colorations. I LOVE everything unusual and unique (as most of you know). However, they are not only beautiful to look at. Sometimes they are a result of mutations or illness. And it can give the animal disadvantages, especially wild animals. For example the piebald deer (not albino but with patches of white over the body)  can suffer from many physical deffects such as bowing of the nose, shorter legs, an arching spine, a short lower jaw and problems with internal organs. Also in the breeding of human pets there are some color variations which might bring problems. The merle color for instance is widely discussed for it sometimes comes with diffrent health issues like eyeproblems.