What does it usually mean when a girl paints her finger nails black?

It has to mean something if girls feel the need to do it, especially black of all colors. I've seen a fair amount of young women do it in high school and college, and no they're not goth or anything crazy like that lol. What does it say about them and who they hang out with do you think, or do you think that has any effect at all?
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+1 y
So it doesn't secretly mean she's a smoker or anything like that? Any of you girls that do it, do you smoke by chance?
What does it usually mean when a girl paints her finger nails black?
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