Clearly German, Irish, etc are not ethnicity but nationality. There is a tendency for individuals to confused nationality, national origin, race and ethnicity. Each one means something different. Unfortunately, too many people use them inter-changeably . Which is part of the confusion.

Bi-racial means just that - two races. And bi-cultural means to cultures.

Historically people have always enhanced their features and/or appearances for aesthetic and cosmetic purposes based on the standard of beauty for the particular society.