[1.1.30] Trains are changing colors by themselves

[VampireSilence]

I always color all of my trains like this:

(R=0, G=128, B=255)

But after some time of playing/saving/loading, almost all of my trains are colored like this:

(R=255, G=128, B=0)

without me changing any colors of course. I don't think that it's intended.

Maybe important: the train error says "Target station not reachable" in german.

[Loewchen]

Provide a save and steps that reproduce the issue please, see 3638.