Yup.
Two years ago I painted the interior
fiberglass cupboards and benches with a sand brown colour and the doors and lower trim green to match my exterior.
After 10 trips, it still looks as good as the day I painted it.
I sanded the fiberglass first, applied the 1st coat, sanded again and did a second coat. Make sure to use a FOAM ROLLER!!
Here are a few pics.