I agree with all the complaints of the bright blue LED. But they don't have to be that way. My amp has a thin bar about 1/4 inch wide and 6 inches long on the face of it. You can adjust brightness. I have it so it is just barely detectable in a moderate amount of light and not too bright in near darkness. Not too bad really.
I remember old gear with lighted dials on tuners. That surface didn't need to be bright so it wasn't annoying. Pin-point leds with a high surface brightness are more of an issue than a distributed panel with a lower level of surface brightness.
For power amps I'm actually okay with no indicator. I mean if you hear sound it is on. I'm okay with nothing for off and whatever color for on. Just please don't give me anything that flashes or breathes.
Now in general for me, green on, yellow for standby or transition and red for off is good because it is like traffic lights. However, industrial gear swapped that sometime in the last generation. Red is on (indicative of power in use and possible danger), yellow is transitional, and green is off (for safe no power). It makes sense when described, but it seems the majority of people think it is backwards in use.
I really dig dash illumination on one of my cars. Orangish-red. Quite fine at night.