If you've got a bad ticket from Garage Editor, you could search its name in HxD. Then the paint number you selected should be right beside it. Reset it to Zero & the ticket should be fine.
The ticket database will be updated & there will be an option to delete tickets/cars.
Maybe duplicate your cars/items too.
I guess you guys got those tickets from the Garage Editor. Deleting them in game is no option..
We are well aware of that and it will be updated for sure. It just needs time.
The only way to get around it would be to reload a backup from the Garage Editors backup folder. Then carefully check if the number of colours is ok for the car to add and not go further..