I'm not aware that mullato and free people of color or free negroes are the same. Free people of color were just that. People who are not considered European who were free regardless of if they were African or mixed race. I think some registers were named Register of free negroes and mullatoes. It appears that might have been the choice of the county as to which wording was used. Just my opinion. The person who probably has more info on this in Va is Selma Stewart. She has transposed several county free negro registries.

Linda