I use black nail polish to cover up bright LEDs (particularly blue ones)
Nail polish; why in the hell didn't I think of that instead of ugly black electrical tape? That's an awesome idea, thanks.
Also, a dark yellow nail polish should make those horrid blue leds appear green, which albeit not turning them off would make them much more gentle to the eyes.
Yup! I used some red polish on one blue led, and it made it into a nice dim purple color. Actually it was quite a nice shade.
I've left a trail of 8mm squares of gaffer's tape covering literally thousands of LEDs around the world. If you ever see a semi-hairless sasquatch -- with what looks like one black fingernail -- climbing naked on a chair, that's probably me.
Or turn it off at the socket so it's not even on standby, using (a small amount of) power all the time?