That’s interesting. I am also red/green colourblind and ok with red. For me though it’s more that greens and browns can be confusing.
I have problems with anything involving green. So yes, greens and browns. Many US green signal lights look dull blue. Also with red, but less so. I can't tell some pinks from grays. And in any mixture, reddish vs greenish.
So blue/green and green/yellow seem like more plausible categories than blue and green. I can see red, but green pretty much looks like bluish yellow.