Agreed, don't want red gold.
This issue just makes no sense to me.
It supposed to be pure gold plus some really minute percentage of something else. The really tiny percentage should be mixed in the gold not on it.
Even if it was on the gold why would it change from a gold colour to red? Gold coloured copper that changes back to it's original red colour. 🤨
It can't be under the gold because gold doesn't work that way or all gold plating would be awful.
Also the sovereigns and Krugerrands from many years ago don't seem to have the issue yet they have a much higher percentage of copper.
I rekon it's must be the Gremlins new batch or 👽👽👽👽