I tend to assume more diversity in cartoons and stories than there is. If there is a character with dark hair and eyes (and only one or two other people in the show who are from an ethnic minority) I will assume that they are Latinos or Asian Americans. It has led to a lot of confusion on my part when casting came out for live action movies or shows and the cast is totally white washed.
I want to avoid that in my own stories. I want diversity in my characters. But it isn't enough to just use "African American" or "Latin American" or any variation in the description. I personally have a fear of my ability of portray different ethnicities. There is more to the cultural experience than the appearance and I'm afraid that I will not do it justice or that the effort I take will fall into (or reinforce) stereotypes.*
In my current series of extremely short stories I have used very little description of the characters. I want people to choose for themselves who the characters are. I don't have specifics in mind, partially because I want people to naturally assume diversity. But in light of this recent event I wanted to tell you the ethnicity I personally imagine for one story. For the short story Cursed from the second I wrote it I imagined Xander Shade as an African American man and his niece Kimmie as bi-racial. Her mother is Xander's sister (African American) and her father is a Pacific Islander.
*One of my comic book heroes, Dwayne McDuffie, creator of Static Shock, Icon, and Milestone Comics, did a lot to spread awareness of this in the comic book industry, and if you have a moment, I highly recommend you look him up.