"Skins," called themes in bulletin board lingo are available for free for any BB software including VBulletin. Better than just a color change, consider adding a variable width theme for monitors both larger and smaller than average. Or better, a variable width theme with this little widget. It lets you adjust the font size from normal, to bigger, to biggest.

In the meantime, when reading is difficult, this may sound stupid, but try highlighting by selecting.

Or if you've got a Mac, control-command-option-8 will change the screen to "night vision" mode and T-I becomes an easy to read dark gray text on white background.