Answer: During slavery, lighter-skinned blacks were privileged while dark-skinned blacks had no privilege. The reason for this privilege is the resemblance of light black skin to white skin. But after the slavery ended, light-skinned people were not considered black enough by the black community, all this history during the period of slavery brought many tensions.
Normally light-skinned blacks are confused and do not understand their place, because for whites, they are black, and for blacks they are not black enough.