Why is the BMW M3 GTR and other cars the wrong colour?

Just unlocked the M3 GTR in FH4 and it’s beige… not silver. I’ve also seen the same thing with the Lotus 340R, it’s beige/ white instead of its traditional blue.

It’s not a game breaker, obviously, but it’s a little frustrating. Getting the right shade of silver on the GTR is pretty damn tough, too.