I think this is a Windows setting; does it happen to all your Office programs? If so, try this:

1: Click on control panel
2: Click on view by: Large Icons
3: Click on "Performance Information and tools"
4: Click on adjust "Visual effects"
5: There will be three line items showing the word "Fade" as the first character string on each line. Uncheck the box in front of each of those three lines and then "OK" everything and back out.