Yeah. That really bothered me too. I tried painting with the G2 red caliper paint, but it's a good bit darker than the upgraded front Brembos. I ended up buying the '17 1LE calipers for the rear which don't match perfectly either but are a whole lot closer than G2 red. And the finish was so much nicer than the ones I painted.
On my car journal I have a pic of the car with the 1LE calipers (page-1) and some pics of the ones I painted with the G2 paint (page-2).
http://www.camaro6.com/forums/showthread.php?t=469102