If you see the reflection of a rainbow on the ground and cross over it, you would turn into the opposite gender.

My informant told me about this superstition when we were talking about the weird quirks that our mothers had.  She told me that when she was a child, her mother had told her about this superstition.  Hearing this, she would always avoid stepping over reflections of rainbows because she did not want to turn into a boy.  When I asked her was her interpretation of this superstition, she told me that she thinks it derived from the belief that rainbows have magical qualities.

I do agree with my informant that this superstition has an association with the belief that rainbows are magical.  However, at the same time, I definitely think there is a connection between this superstition and homosexuality.  Currently, rainbows are commonly associated with the gay rights movement.  This superstition seems to reflect a fear of becoming a member of the opposite sex and gaining the traits that are associated with the opposite gender.  With this interpretation in mind, it is easy to see why the LGBT community has chosen the rainbow as a symbol to demonstrate their non-fear of crossing gender roles and stereotypes.