Table Coding Help

So, I'm trying to get a better table for this forum I'm on.. As well as my own. The only problem is this forum is slightly transparent, so you can see the forum background through your posts/images/tables and whatnot.

I was wondering if there was a piece of code I could add to my tables in order to make my background image non-transparent.. Or, you know, normal. I don't want to see her forum background under my table background when I post the table.. Not sure if this is possible, but I thought I'd ask. It'd be handy for my forums too.

I'd post an image of it, but my account is new, so at the moment I'm unable to.

So you what a background only on tables posted in messages?