[disillusioned]

They sell LED dimming (and blackout) stickers on Amazon, and those things have been a lifesaver for me. My new USB-C charging block is brighter than the sun and the LED is functionally useless, so it's been masked with the blackout version of the stickers, but my Dyson fan which has a blue power LED (which turns to red when it's on heat mode) and BRIGHT WHITE LED temperature readout in heat mode has gotten the dimming treatment. Nice because you can still see the light, but 80% less bright, so I can sleep at night.

[russellbeattie]

Dedicated stickers are probably the nicest option, but I've just used black electrical tape to completely black out a lot of blue LEDs electronics - especially in the bedroom like you. If you want to see the light, a few pinholes are enough to let some light through.

[bpye]

I seem to remember the early SiFive HiFive boards coming with a sticker to put on the insanely bright blue power LED on the board.