i would get specific interior paint to do this. its not so much a paint as it is a dye.
for the door panels, pop out the door cups (be careful not to break the tab at the bottom). two screws remove the buttons from the cups. push the handle cup out from the inside. there are two screws hidden behind the door cup, remove them. Then on the door jab hinge side there is a plastic friction pin, pull that out. Then lift the door panel up and out slowly because you'll have to disconnect the power lock harness. fairly simple to do.