Plants on the inside of Haernamë totally get to be red.
Actually, I've just convinced myself that based on worldshine, one half of the torus should have green plants on the inside and the other* red, because the red side gets to absorb the light reflected off the green plants and vice-versa. Of course, daylight would probably dominate worldshine, but if sunlight's yellow and thus made of both red and green light equally, it'd totally work.
*: Specifically, the dextrize hemitorus, where everything that's happened so far has taken place.
Actually, I've just convinced myself that based on worldshine, one half of the torus should have green plants on the inside and the other* red, because the red side gets to absorb the light reflected off the green plants and vice-versa. Of course, daylight would probably dominate worldshine, but if sunlight's yellow and thus made of both red and green light equally, it'd totally work.
*: Specifically, the dextrize hemitorus, where everything that's happened so far has taken place.