user_color_scheme_class with no current_user
Created by: docwhat
This refactors the user_color_scheme_class
to use a hash with a default.
This prevents problems with workers that don't have access to the
current_user.
Fixes issue #2758 (closed)
The previous solution (commit 84e4cfc6bbfa7251dc8e2b88ca4c507b98cadc61) returned a number, not a string. I also added unit tests for it.