Customizing Topic Posts

I had found a topic on here talking about the same thing but the link that an administrator put was expired and so it wasn't really much help for me, but I'm wanting to use a custom background on topic posts by admins so instead of the plain regular background it would like for example when administrators reply the border of their post is Red, Staff is Green, etc...

I tried to explain the best I could about what I mean.

@Rondell http://fmdesign.forumotion.com/t230-add-a-classname-to-group-member-posts

you can change the css to include background images or border colors

credits to ange tuteur

Ace 1 wrote:@Rondell http://fmdesign.forumotion.com/t230-add-a-classname-to-group-member-posts

you can change the css to include background images or border colors

credits to ange tuteur

I done exactly what it said to do but it didn't work.

EDIT:

Not sure what I'm doing wrong exactly, I've looked it up and done multiple different things from different people and nothing seems to work for me.. 
I do have the code on my forums which will put a verification mark on a users name depending the group they're in, for example "Rondell " in the CSS area, I removed it and tried doing this and still did nothing.

Bump? It's been 2 days.
I'm also using ModernBB if that helps with anything. 
website is http://itrknet.forumotion.com/

This isn't needed anymore.. if an admin wishes to trash this topic.