Change in border size and bakground color in the comment box

I have just installed Gallery2 and im quite impressed!
Im using the ajaxian theme.

My problem is that the commentbox color and the background color of the pages are the same.
Its hard for people to se the comments since they are blended into the page.
I want to make comment boxes to be more visible.

So im wondering how to for instance set a border and/or add a different background color for the comment boxes.

Thanks for all your help in advance!