Not a whole lot going on here. My buddy sent me this photo of his AIO. Backstory is – The Pump went out. But, the temps remained okay. He kept using the PC for about 2 years. There's still no performance issues. He was only using it for streaming music and web surfing. Doesn't play games on it. Upon removing the AIO to finally service the pump and clean everything up. He spotted the weird discoloration. Doesn't use liquid metal. I've never had a copper AIO without a de-lidded CPU. So, i don't know what exactly i am looking at here. Just a gut feeling telling me it's electrolysis.
Thoughts?