Everyone had Tetrachromacy, but then early mammals dropped down to Dichromacy or even Monochromacy. The dichromatics split up to the Americas and Afro-Eurasia, and they both evolved, through convergent evolution, different ways to acquire trichromacy to different extends based on their environmental needs =) - a summary anyway.

And yeah red pandas look nob-all like giant pandas and are way more productive members of society!