When will this country(U.S.A) stop using biracial people to represent black folks?

i'm gettin tired of all these movies,commercials always using these half breeds to play us blk folks it is sad and proves how racist america is why are they so afraid of black people and what is the message they are trynna get out? that we blk people cant be beautiful unless we are mixed? thats b.s and it is sicken me that every movie or commercial i have 2 see some mulatto girl playing a black girl when is the ignorance and racism of hollywood,the media and music videos gonna stop?