Hi. I Have A Brownish Copper Looking Mark In My

Hi. I have a brownish copper looking mark in my palm and inner wrist. It kind of looks like an ink stain or something.
It doesn't wash off. Isn't raised and has never itched. I've just noticed it there. I've gotten these marks in my hand for as long as I remember but I am unsure as to what they are. They usually fade in a few days. But come back in a different shape and size and location on my hand.

What could it be and should I seek medical attention for it.