I'd go with not enough light because the polyps should be red not brown. The body should be a pale or baby blue so I wouldn't worry about it being bleached if it looks light.
Most likely not enough light, but browning might also suggest high nutrients. I see some brown fuzz,that looks like algae , that usually is a sign of high nutrients.
The Monti is middle of the way up. Far side of tank. The light is a radion g3 pro. Doesn't hit it too too much. But a fair amount. Nutrients as in Phosphate? Probably . 03 it's encrusted already so I can't move it. Maybe I'll do a decent water change and try to get some more light on it. Or just break a piece off and start a new colony. Thanks.