Eric Fischer has created fascinating maps of the biggest forty cities in the United States illustrating ethnicity by small color dots — White is pink; Black is blue; Hispanic is orange, and Asian is green. He originally used 2000 Census data, but it appears that many, if not all, have now been replaced with 2010 data. You can see them all here.
Here’s his map of Sacramento:
I’m adding them to The Best Tools For Analyzing Census Data.