This term originated when Trevor Phillips first learned about the country Montenegro from a native of that country who was visiting the California State University East Bay. He wondered about what the people called themselves. He came up the theory that they must be called "Montenegrins". Telling people about this rather humorous word, his friend Karl Rogers II shortened it to emphasize the funniest part of the word.
In no way is this word as a racial reference; It originated from the mind of an African American teenager.
Karl: Wow, you're acting like a fool right now ya' Negrin.