I agree with MERXLE, taking at least an hour for an Oxidized Copper Golem to become a statue is an extremely long amount of time. It’s also out of parity with how it works in Bedrock Edition, where once a Cooper Golem is oxidized, it takes about 10 seconds to become a statue.
Confirmed in 1.21.111, now with an even more egregious example. Spruce shelves, which are designed to match with their respective stripped logs, are colored properly, causing this to happen.