the 4 Queens had a bi-color chip

one side red the other purple. the rim looks like this.

what does your rim look like? is it green , tan, or faded green?
my guess is the chip started out green . then drilled. then sometime put in a frame on a wall .tan side was the sunny side, the hole was exposed to uv, and the green side got reflexed uv from a white backer.
the hole looks to be a 1/4 inch i would bore the hole out to 9/32 or 17/64 maybe as large as 5/16 slowly and carefully to see if it is green.
also uv tends to lighten colors red -orange , orange -yellow , purple - violet ...
my guess uv fade.