Oh, yes ! The kit you show is mine... I built it in January 1985 a time when I still believed all that was written by "experts". Yes, there has been G-6ASs with red wheels, but I think only at the very beginning of delivery of this model to let know they were DB 605 AS-powered. But with the growing number of DB 605 AS and D powered planes, I think red wheels were dropped.
If you look, on "white 7", at the first exhaust pipe which is officially black you'll see it's of a light shade... Personnally, I think the wheels are not red neither on JG 300's plane nor on "white 7". I'll repaint the wheels of my kit black. A greyish black such as RLM 66.
Bur I must say that red wheels are more beautiful...

Cheers,
Jicehem