AfriGeneas Western Frontier Forum
Some informal statistics
Decided to play and see, informally, what ancestry indexed for the 1870 Census.
Ancestry's indices for the 1870 Census are sortable by white/colored. In Minnesota, at least, Indians were not counted as colored.
In some of the other states, Chinese made up a large proportion of those indexed as "colored" (number indicated is those listing birthplace as China)
These are pulled from a quick search at ancestry (has a search choice of white or colored) of the 1870 census:
State # of Colored Residents out of Total
Arizona Territory 21 out of 9658