Michel van Peenen
I'd be surprised. Those colors/train types are spread around the board for clearly evident design and gameplay reasons. There may be some coincidental link between a few segments' train types and the cities they connect, but that's it.
I think Barneyg is correct because TTR Europe uses different pictures for the wagon and locomotive cards, see:
image by 7ofAnn
image by Matt71
Some are new types (green card) and some are just mirror images (purple card)
I think DOW planned the Marklin edition from the beginning and just picked some pics from the Marklin railway model catalog.