Hopefully finally fixed constexpr issues in ColorTest with GCC 4.6.
Hopefully finally fixed constexpr issues in ColorTest with GCC 4.6.

Follow-up to 80b61be4851910d575547516e6ce75b883aca4a4, I am too lazy to
test it before commiting.

MiUishadow/magnum,ashimidashajia/magnum,ashimidashajia/magnum,DerThorsten/magnum,ashimidashajia/magnum,DerThorsten/magnum,MiUishadow/magnum,DerThorsten/magnum,ashimidashajia/magnum,MiUishadow/magnum,DerThorsten/magnum,DerThorsten/magnum,MiUishadow/magnum,MiUishadow/magnum,ashimidashajia/magnum,MiUishadow/magnum