Lets clarify and expand my post above so you understand which way you want to go. I gave you two answers above and you can decide what you want to do in your circumstance.
One involves from a support manner I stated you can change your color by editing the appropriate class in your vbulletin stylesheet to change that row color. The tcat class specifically is that class
Now number two involves you modifying your codes html to display however you wish and that is code modification.
From a support perspective this issue has been answered. You would alter the vb
style class directly and change that color.