Was there ever a Pokemon game based off the Orange Islands?
There is no game located in the Orange Islands. Perhaps the closest game would be Fire Red/Leaf Green where the player could explore Sevii Islands. There are arguments that this was inspired by the Orange Islands, but I haven't found any proof.

There have been player modded games fitting in with the Orange Islands - Example, but no official release. Reference

According to this answer on another site, the Orange Island plot was half-hearted and this probably meant that there was no real push for a related game on that end.