As stated above, bring a brush, not a can of spray paint. Overspray really looks bad.
Actually... just bring a template.. ours is made form the cardboard of a sierra nevada 12 pack of cans, made a little cut in it the same shape as the hanger WALA! Perfect painted hangers everytime! That photo above is messed up... at the very least TRY to match the paint to the wall color - it almost looks as though the person was like well fine if I have to paint my hangers then im gonna do a shit job on purpose.
I've tried latex primers a few times. Seems to peel off easily. Can kinda work. Easy for me now as I just buy stainless...
The latex primer doesn't work all that well. Just use the plain old Latex Spray Paint and skip the primer. The H2O Krylon works well. I've used it on both PS and SS and it sticks better than anything else I've tried. Key is to give it plenty of time to cure and harden.