PS4 Dualshock 4 light bar will never be off.

[SvennoJ]

It's annoying when playing on a projector. The blue light reflects on the screen screwing up black level. It's interfering with the darker levels in KZ SF, black is not black anymore but dark blue instead.
Since it's winter I simply stick the controller under a blanket, problem solved. If there's still no off option by the time it gets warm again, I'll put a piece of tape over it.

I have used it too as a flashlight occasionally.

I've not seen it reflecting in the tv in the living room, and the kids love it. So I won't sever any internal connections to get rid of it.