Yes. For those who wear rings, bracelets, or even bands for too long, the residual surface accumulation causes skin irritation and lower absorption. Over time, toxicity causes cancerous cell growth. You see this all the time with Asian people wearing "holistic" devices and suffering some odd reactions and toxicity in their bloodstream. We use copper sulfate to treat algae around here, and those who are foolish to drink the water straight up without knowing, especially pets, they suffer kidney and liver damage.
The discoloration is cellular toxicity marking. It's not metal leeching discoloration, but metal-base skin irritation due to overloading the tissue capacity to get rid of the accumulative metal on the skin.
For me, I wouldn't even wear any device like that. Magnets, maybe, if there's a ceramic coating. Direct metal to skin, nope. It's more critical to have the supporting metal in proper value inside the body than from the outside. Your body knows when to release it through poops and pees, but you can't control it when the body gets bombarded with the metal constantly at one point.
Trust your instinct on this one. Your body is telling you of the toxicity that is happening on your body.