Are Silver Grey and Sparkling Graphite that hard to match?

Im in the market for a ZHP. Likely a sedan, but regarding Silver Grey and Sparkling Graphite cars: So why is it that so many of the coupes front and rear bumper covers do not seem to be color matched to other panels? Are the colors just too hard to match?

Metallic colors are harder to match, I believe...
Both are metallic.

Also keep in mind that the bumpers aren't metal, so paint isn't going to look the same on those body parts versus the metal parts of the car. On mine, both front and rear bumpers have faded some, while none of the metal parts of the car have faded paint.