Honestly, there is a difference beween variations and mutations. I would be very disatisfied if the improvments regarding diversity in animals end up being mutations instead of natural variants. Mutations are a hot topic in zoos and rightful so. As an aditions to natural coat variation, I wouldn't mind though.
You are actually mixing things up a bit here.Most people associate something bad with the term mutation,because it is depicted that way in various contexts (through media,movies,the colloquial term "mutants" etc.)
Every difference in e.g colour/shade,fur length,eye colour is a mutation on it's own;the difference is just in what genes and thus pigments etc. are affected.
Overall mutations are not a bad thing at all,they are occuring all the time and they are the reason why our planet is not full of clones.
Some mutations are known though to being more fond of being related to/causing health problems (e.g. albinism) etc. or in the animal case being a case of inbreeding to achieve a large mass of them and that's why there is so much focus on them.
A darker orange coloured tiger has a mutation in the distribution and quantity of the responsible pigments (mostly melanin),just like a leucistic (white) tiger has.The difference is only in the actually resulting mutation,but both individuals do have one.
Regarding the thread: It's about overall colour mutations and "normal" variants (even if those are actually the same) ,not only about the big ones like melanism and albinism.