Keyboard backlighting fails intermittently

Once in a time I have problems with backlighting of the buttons on my Remote3. When the button backlight brightness is above 50%, I have no backlight at all. When the button backlight brightness is under 50% I have backlight. Only get all kind of different colors between green and red and not in the requested color white. After restarting the Remote3 this problem is away, but after a while the problem is back again. I am on the latest firmware 2.8.3.