Hackish, map the colors for the glyphs

I couldn't find public API to get the colors array (maybe I am blind)
so just added a derived class that really just exposes that array. This
enables color mapping in the Glyp3D mapper and more tests pass. Much of
the API is temporary - Ken we should chat about the best approach from
an API standpoint.

Change-Id: Ieed46918fb24de6b42d93896d581bdd660a0b174