72116342_Grand_Theft_Wiki__the_GTA_wiki__Description
[Ability] Permanent Color [Code] Permanent Color [Description] 
This means that the car has a permanent color, if you go to the Pay N' Spray, the car will be fixed, but cannot be resprayed and not change into another color. However, none of the vehicles with permanent color can be saved.
Difference between revisions of "Special Vehicles" - Grand Theft Wiki, the GTA wiki