Change b/g of post for OP's replies

[Morrus]

I've started an Ask Me Anything subforum based on the Reddit concept.

To make it easier for folks to find the interviewee's responses, I figured it would be useful to change the background colour of their posts (but ONLY in that forum). Something like the b/g colour change that comes with selecting a post for mod action.

Is there an easy way to do this? I know there are some "highlight thread starter" mods, but they all jst add a label or graphic, whereas I want to actually highlight the entire post area to make it really easy to find.