As I look at this chart, I see much bound by history and geography. Norse Gods of Medieval Europe, German bad guys, a Russian agent are all Caucasian by definition
Marvel comics is arguably the most diverse medium in entertainment. Gabe Jones, Black Panther, Falcon all put in major parts in the 60's. Women became prominent heroes in the 70's as well as Power Man, Shang Chi, etc. There is more than enough diversity present in their characters and they will be expressed as the Marvel Universe grows on screen. The entire X-Men catalog is all about wiping out prejudice and hatred. Personally I think it would condescending to change a character instead of creating a character or using an existing one that already fits the description. When my brother and I went to see Avengers we brought the kids. My nephew who is half Japanese, brought his 2 best friends, a boy from Africa and a boy from India and all anyone saw were heroes and villains, not white, black or Asian characters. If things go right and we eventually get Iron Fist on screen he can share a passionate on screen kiss with Misty Knight.