When presenting data in a table, vBulletin will usually alternate the background color of cells to assist in readability.
The background colors used for these two alternating cells are controlled by the First and Second Alternating Color classes.Generally, you will only want to control the background color field for these classes, although you are free to use all of the available fields to achieve any effect you desire.
Example of element using these classes:
<table class="tborder" cellspacing="1" cellpadding="6"> <tr> <td class="alt1">Tag using the First Alt. Color class</td> <td class="alt2">Tag using the Second Alt. Color class</td> </tr> </table>