You can and it works great!! We have had this sad white bathroom door for years. It was dingy (boys with dirty hands will do that) no matter how much we tried to clean it, it just looked grubby so I made an executive decision to spray paint it and sent Hubby off to Home Depot for supplies.
He came back with a trigger sprayer and a few cans of celery green paint.
Tape the knob and spray away. Flip, repeat. Hang and admire.
ahhhhhh - - You have to trust me that it looks good because my Autistic son likes to peel paint and the doorframes look reeeeeally bad. When i get a chance to repaint them, I’ll take a follow up photo. *sigh* The project list continues!