MTV debuted August 1, 1981 airing The Buggles’ “Video Killed the Radio Star” followed by “You Better Run” by Pat Benatar. The first video to be banned by MTV was “Girls on Film” by Duran Duran in 1981. Notably missing from MTV during its first couple of years was any video by a black artist. MTV executives claimed that, “few black artists recorded the kind of Rock and Roll the channel played.” Finally, after immense pressure, Michael Jackson’s “Billie Jean” became the first video by a black artist to be aired on the channel.
From Wikipedia (http://en.wikipedia.org/wiki/Billie_Jean#Impact_of_song_and_music_video): In 1983 Jackson and CBS Records President Walter Yetnikoff informed MTV’s president that if the cable channel didn’t play Jackson’s video, CBS would not allow them to play all of their white artists who were getting exposure on the network.( most notably Ozzy Osbourne and Billy Joel.) With that ultimatum, MTV finally bowed to pressure and premiered Jackson’s “Billie Jean” video on March 10, 1983.
After that, the wall came down and MTV agreed to include black artists in its rotation paving the way for Lionel Richie, Prince, and Janet Jackson.
Here is a college paper written on the topic: http://www.indiana.edu/~t311/timeline/1980aswart.html