The official story is you can paint over it if you do it before it totally cures. So apply the POR-15, let it dry for a few hours (4-8 hours?) until just barely sticky, then coat it with something else. If you need to paint POR-15 later, they sell an etching primer for that. I've primered and painted over sticky POR-15, and also bondo'd. Seemed to work well. I never tried to paint over old POR-15. Maybe someone else has and can say if it works?
