But, for real, OP is having a struggle with it for this reason.
If something is 50% G and 50% B, it is neither one or the other. It's exactly where C sits. If it is 75% G and 25% B, you could say it's green. But if I asked if it's green or cyan, we'll have the same issue again, sinc it's. 50% G and 50% C.
Cyan is a primary color when working subtractively, but for additive color the primaries are RGB. Since this is on a screen, green and blue would be the relevant primaries