The bronzed finish on a middle aged woman's labia minora. On a typical Rusty Cunt Bucket, the flaps will be loose and hanging low, swing low sweet chariot. Also used as an insult or in venting fury or road rage.
When I went down on my wife the other night the room was dark and I could smell a bucket of rusty nails. Then I realized she just started her period causing me to get my red wings.