XP Pro
Things to know about the accessibilty Wizard locaed under Start > Programs > Accessories > Accessibility
When this setting is enabled you will loss the ability to see the cell colors in Excel.
http://www.disability.illinois.edu/services/at/index.php?sub=34
To restore the cell colors in Excel:
Start > Control Panel > Accessibility Options > Display tab > uncheck Use High Contrast
http://support.microsoft.com/default.aspx?kbid=833258
Another place to control High Contrast:
Display Properties > Appearance tab > Windows Classic Style > then High Contrast