You're basically talking about RBP (Ridge Blue Pearl) which was a common and desirable color on the gm6/gm8 ('gc8') 2.5RS's from the late 90's/early 00's.
Should look up some of the older builds in the GC thread in the car gallery and see what worked.
Look up Adamsrs, red worked well on that car.
But my personal choice would be flat gunmetal (similar but maybe a little lighter than the Work wheels color - which people use Duplicolor Engine Enamel Cast Coat Iron as a substitute for). Brakes that color + red lettering = Brembo monoblock race caliper style