Robert Downy Jr goes black??

I dont know much but i think this is kindda racist...coz if you're white you cant go black..but Robert Downey Jr had shocked us when he became black in the movie Tropic Thunder..i wonder if they use normal car spray for that...i've been testing it to my rabbit and now i cant change it back to white... this is robert downey jr....in White Mode

Spot the difference....easy..BLACK AND WHITE...but he kindda look different,like totally diferent..i also notice the black Downey chin is a little smaller than the white one...wow..the makeup artist is sure a professional...