The color table attributes are never used in a type checked
environment, only via setattr/gettattr so dont create individual
get/setters for them. Reduaces the import time for this module from 2ms
to 0.7ms
Since attribute access is implemented via __getattr__ there should be no
performance implications for normal attribute access, as __getattr__ is
only called if normal attribute access fails. setattr becomes slightly
slower but that is done very rarely.