On large car rims it is the portion of the inside of the wheel that is painted usually to match the cars paint job.
T: yo.. check out that green 64'
V: ahhh tight, its even gots da lip stick on the rims!!
When a male dog becomes aroused and "unsheaths it's sword" resembling an extending lipstick.
"Dude, that dogs is humping your leg."
"What do I do?"
"Oh... here comes the lip stick!"