Quote Originally Posted by i_amtrunks View Post
Definitely part of his redesign, but I think it may also be to further distinguish him from Thanos in the Avengers movies.

I know they don't look very similar to to the movie fans it might be enough to confuse them.
There was no need to give Apocalypse blue skin to start with because it's always been gray.
Furthermore (just a subjective gripe) his voice lacks the presence I remember from the early 90's cartoons which is where I first encountered this villain.