Problem: Eyes get tired when looking on white background for many hours. Visual studio white areas, MSDN Library white area background for articles.

Solution:

Visual Studio IDE. Can set backgroundcolor to e.g. lightgray in one place so background color in all windows in IDE are affected.

MSDN Library web site. The preferred background color can be remembered in a cookie e.g.

This is nice features to have for software developers who use Visual Studio and MSDN Library a lot on a working day. Other websites and other applications on the host are not affected compared to solving the problem with dimming the display brightness or changing windows system colors.

Adobe PDF reader has a similar feature where "PDF paper" can be set to gray instead of white (255,255,255). Nice for the eye ;-)