I have a skin tag that turned blackish purple, what does this mean and what should i do?

Black Skin Tag: Accidental pinching or twisting of the tag could restrict blood flow to the growth, leading the tag to die and turn black. Though likely still harmless, schedule an appointment with a dermatologist to have the growth examined and possibly removed.

Watch and wait: It will likely fall off. If you develop a sore or a nodule at the site, see a doctor.