I found this in a few different places around the 'net - hopefully it's helpful:

Turn on High Contrast

High Contrast is designed for people who have vision impairment. High contrast color schemes can make the screen easier to view for some users by heightening screen contrast with alternative color combinations. Some of the schemes also change font sizes for easier reading.

• Click Start, click Control Panel, and then click Accessibility Options.
• On the Display tab, under High Contrast, select the Use High Contrast check box.
• To turn off High Contrast, clear the Use High Contrast check box.
• If the Use shortcut check box in the Settings for High Contrast dialog box is selected, you can turn High Contrast on or off by pressing the left ALT+Left SHIFT+PRINT SCREEN keys (depending on the other settings you have selected in the Accessibility Options dialog box).
  
• To open the Settings for High Contrast dialog box, open Accessibility Options, click the Display tab, and then, under High Contrast, click Settings.