just my opinion , dick can be colored by various reasons other separated parts too.
not exclusively "If your biological parent and/or grandparent is a non white you are not white"
but also if u can track anyone down the line who is not then u are not pure . let lone 1/4 - 1/8 this include all the people who have mgm generations at some point , this rule apply with any race .
and it's not only the color does, ethnicity define more .