I also used G2 paint on my rears. Have been this way for 60k miles. no discoloration, but I clean
 

them often (actually all the time). They look like I just painted them. Again with the proper prep work and regular cleaning they will last a long time. Get the G2 paint and follow the directions (but dont mix it together all at once, only mix enough for the caliper you are working on). Take your time and dont rush. Let it cure longer then it asks for. If you have any questions I would be glad to help. Good Luck.

Yea sure let me know. I have just had the G2 kit sitting around my house the whole time.

Silver with black decals

If you are going with decals then use the G2 paint & a high temp clear.