This is a WAG on my part. I believe the wallboard has a synthetic covering that is attached to the extremely thin fiberboard behind it. I would think that whatever paint you might use must be compatible with synthetic/polymer/plastic surfaces.
2012 F350 KR CC DRW w/ some stuff
Cindy and Tom, Toby and Kasey (our Berner and Newfie)
Oh...I forgot the five kids.