I'm calling... 8-bit and Orange. 8-Bit is a new colour people seem fond of, and it could work on a fairly solidly built pet like the Kacheek. Orange is such a basic colour that I'm surprised it hasn't been released already.
I'm calling Maraquan and Silver. Or maybe Gold. I think TNT have been filling out the "metallics" on purpose, and Maraquan feels like it's overdue for another pet. They could well go with one of the newer colors, though i wouldn't be surprised if they gave it a rest for Kacheeks for now. And in a way, i wouldn't be surprised if they went hog-wild and put out three new ones instead of the standard two.
I went with Maractite and Silver. Mainly because there's lots of Kacheek there to put a very detailed and beautiful Maractite pattern on. But really, it'll probably be something else.