You know that show where they did an experiment and found that people have trouble identifying people of other races. I think that is so true. I have two coworkers and other than being black and female we look nothing alike yet white people are always getting us mixed up. One lady is tall, dark skin, early 20s and super short hair. I'm short, in my 30s, light skin and longer hair. The third is dark, about my height but at least 30 pounds heavier than I am and probably 50 pounds heavier than the tall lady. Yet somehow we get called eachother's names often. Very annoying. Plus the other two have distinct New orleans accents and i don't. And I have noticed this mistake of mixing us up almost never comes blacks or other minorities. It is to the point that sometimes I don't bother to correct people. I just say "ok" and move it along. Now I will say I have a friend who is white and has a bunch of sisters and I get them confused because they are so many and they look alike to me. But I either ask or don't call a name. At least they are related and they even admit they resemble.

Edit - I'd like to add if I was being constantly confused with a relative or someone who actually favored me I would be okay with it. I understand confusing Jessica Simpson with Britney Spears. But if you can't tell Charlize Theron from Natalie Portman you need to go to the eye doctor.