Being tidally-locked may mean that not having any Van Allen belts may be irrelevant: the radiation they're being bombarded by is coming from their sun, & life could evolve on the opposite side, having warmth, & maybe photosynthesis at the daylight-horizon?

Now that's cool to think about. What if there's a large ring of life around the daylight horizon that hosts complex organisms (would plant-like organisms have red chlorophyll?), and to the sun-facing side everything becomes a constant, immense blare of red light, x-rays, and UV radiation; and to the dark side is constant darkness broken only by the stars, and maybe some fungal/bacterial lifeforms and stuff that can feed on them.

What color would the horizon be? Like the "sunset" of a red dwarf, would it shift to blues and greens and purples or just be invisible?