Not really, some people put rainbow hair colored people just to create people that are ethnicity-free so they can avoid all labels and stereotype the comes with the ethnicity. In the end, it all depends on story.1. Are there ethnicities that you'd like to see more often?
If having a different ethnicity plays an important part in the story, then yeah I'm all for it. If the character has a different ethnicity just as a way be being different, then no. I'd rather have a usual set of people and have the writer work on their personality.
Captain planet is a good example. They have 1 characters from each area of the world to bring multi-ethnic groups. And made the superhero a green haired, blue skinned, weirdo in red tights.
If captain planet was a white skinned/dark haired/blue eyed person like super man, how would people's opinion change?
Kind of hard, in media. People are have some kind of expectation to different ethnic groups. Indeed you can create a character with a off-norm mixture of personality/heritage, but you'll have to work extra hard to make it work and believable to the audience.2. Do you think that it's possible to keep to a non-stereotypical personality without the character losing their 'heritage' in a way? xD