Chrizzly Plarail/HiT released him with grey wheels, but when Fisher-Price gained the licence, he was sold with black wheels, which were the colour on his actual model in the TV series.
Super Thanks Chrizzly What really confused me was the rear, fake truck wheels which on both have it as white. I thought maybe there was something in a story that had him change wheel color.
Chrizzly No, they just moulded and painted the body shell the same and only changed the 'real' wheels.