In netscape the default background colour used to be black on light grey. I find that much easier on my eyes than black on white. Even a light yellow with dark green text. But given a dark room I like to switch the other way. See how you feel with a terminal/editor in different colour schemes. So bright room, bright scheme, dark room dark scheme. What I can't stand is flipping between the two modes. At night on a phone, some apps are incredibly painful to read. Even darkish flavours can be ruined with bright splash screens. There's just no consistency here.