Hi. I have recently noticed my husband's gums are turning a purple colored black. Its not the whole gum, and it almost looks like you could wipe it off. His teeth are really good other than that. He is a heavy cigarette smoker, and a daily weed smoker. I am not sure how long they have been this way but I just noticed it tonight. He is white, black hair with brown eyes, darker completion. He is 28 yrs old, and has been smoking since the age of 13. Thank you.