Another option is nail polish. It comes in plenty of colors and you can add a thin layer of polish to make the LED dimmer but not totally blacked out.

There's a reason you find a matching color and cut the smallest piece that covers the LED, I haven't seen any aesthetics ruined by tape if they already have an ungodly bright blue LED indicator.

I have a set of various colors of electrical tape. If the color is even close to the same, you can't even tell it was there unless you are looking for it.