Can you decide to put a person of the same color as one of your rides back into the visitor pool and play a non-matching color (Info Stand). This came up in our play because of the use of the info point stand.
The person had a purple space open and got a blue and a purple visitor from the bag. To avoid collecting dirt next round, he returned the purple to the visitor pool and placed the blue visitor on his purple ride because of the Info stand.
Clever play! I don't see anything in the English rules that would forbid it, so I'd consider it a valid strategy.