How does Rita Mae Brown use imagery in Rubyfruit Jungle?

Imagery:

After the storm, the sky stayed dark but across the horizon was a brilliant rainbow. […] Leroy bet me I couldn’t find a pot of gold at the end, and I told him that was stupid because the rainbow was enough.

Oh well, maybe the only beauty left in cities is in the oil slicks on the road and maybe there isn't any beauty left in the people who live in these places.