I don't know, but I have the same problem. When you find out, let me know...
Brief contact with silver nitrate creates brown, black, or purple stains on the skin, but increased exposure can cause burns.
Yes, sometimes women can cause this by their own discharge, or, just before or after their periods. Even if the sheets are washed the stain can be hard to get rid of. I wouldn't get too excited or worried over it.
I read on one website that the food and water we consume has a varying level of acid in it, if the food we eat has a high level of acid, then our sweat and bodily fluids can actually cause a discoloring stain depending on the dye in our sheets.(acid in the skin reacts with the dye).
I'd have described them as more of a yellowish-orange, myself. Ninhydrin reacts with amino acids. Amino acids are all over your skin. With most of them it forms a yellowish compound; with a couple it's more of the blue-purple you're describing.
No
cause your mom is purple! ha
copper and alloys of copper
Glaciers
RuffleRustleFlapBillowSwellBulgeBalloon
In winter I change the sheet set weekly...in summer twice or three times a week. More if you sweat at night. They also should be washed in hot water, to kill all bacteria left from your skin. Remember not to use chlorine bleach with colored sheets; always use color-safe bleach. There are many people who only change bed sheets once every couple of weeks or once a month. If you don't have terrible allergies from dust mites, and your bed sheets aren't soiled, it's not likely to cause huge problems if you wait a little longer to change sheets. You should replace your sheets completely, getting rid of the old ones, when there are holes, stains or bleach stains, or the edge of the fitted sheet starts to come apart at the corners.
They like purple (most of them)They are smart 'cause purple is so awesome-----Anonomous
when you're cold your lips will turn a blueish purple