Gilbert Baker created the original Rainbow Flag with 8 colors in 1978. Since then he has continued to work on evolving the Rainbow Flag. The rainbow flag most people know and recognize as being a symbol for the LGBT movement has 6 colors.
While not a legal source or a source that should be cited in legal works, Wikipedia has information on the history of the Rainbow Flag.
Lesbian, Gay, Bisexual and Transgender (LGBT) law covers a wide range of legal issues including but not limited to: recognizing same-sex marriage or partnerships, hate-crimes, parenting and/or adoption, anti-bullying, same sex relationships, etc.
LGBT rights are often under the umbrella of human and civil rights.
The reference department would like to thank Michaella Levandoski for creating this guide. It is updated by the reference librarians.