Where are user-made paint colors stored?

When you create and save a custom color it's in the "user" list below the list of the selected vehicle's stock colors, but I'm wondering, where are these user-made colors saved?

I assumed something like documents\beamng.drive\vehicles or documents\beamng.drive\settings or so, but I can't find any file that mentions these colors.


(these colors I mean)

 

Thanks!