Only double the color with color doubling

Not the alpha.  Thanks to @raven02.

This improves Final Fantasy Type-0 (demo at least), and Kingdom Hearts colors (not lighting, but e.g. the hard menu alpha.)

A surprising (to me, at least) number of games use this color doubling, which weren't hurt by this change:
 * Tactics Ogre
 * Dissidia
 * Jeanne D'Arc
 * Ys Seven
 * Hexyz Force
 * Shadow of Destiny
 * Legend of Heroes 1
 * Crisis Core
 * Mana Khemia
 * Cladun X2

-[Unknown]