Green is too close to yellow in some LED colors, so if you have a yellow indication for an issue with the devices it’s far easier to separate blue-yellow-red indications than green-yellow-red, especially for those who make have deficient color vision.

I once slept in a hotel room where the TV had a blue LED standby light. I had to go and cover it up, it was way too bright.

You guys in these comments should all buy light dimming stickers

I have a microphone that when plugged into my computer, even if the computer is sleeping, shines a bright blue light that cannot be covered up without removing the sticker covering the screws holding the mesh in, so I just put a pair of socks on top of it as a 'temporary' solution

I don't charge things at night since I don't like to be asleep when a battery is charging. This conveniently makes it so I don't get to see a charging light at night. Everything else is on a power strip with a switch. My bedside light and alarm clock are the only things plugged a power strip without a switch.