Recently, I've found the "over-bright" setting in the advanced video options: it basically removes (sun)light reflections from the world textures and darkens the sky at day.
While I really like the "cleaner" look of the non-reflective city (although I change back from time to time), I'd certainly like to see the shiny sky and the blinding sun above the non-reflective world. Is there a useropts command that allows me something like that?