1. They ran out of paint.
2. They were interrupted while doing their nails.
3. They are hiding an actual black nail underneath.
Sorry, did not mean to be so flippant. I really don't know.
It's represent hope during tough times and it's your ring finger
Personally I paint my middle finger black to represent my pain and sadness I use it to show I'm different guilt loneliness tears my mind plus I'm a self harmed so yeah
it ususally signifies their individuality. they're different from everybody else, so they show it by their nail polish. ever seen avril lavigne or andy six's nails? they have one nail painted red, and the rest blac. to show that they are different, and that they are their one person. i usually paint my left thumb black, mainly 'cause it's different and i think it looks good.
Just trying it out to see how it looks and too lazy or doesn't have polish remover to remove it.
Trying to make people wonder what the significance is?
it's their Finger of Power (if on the middle nail) haha