Or at least I hope it's CSS.
To highlight an official post, instead of turning the whole post background into a poor contrast / washed out version of the color we all know and love... how about you stick with the main forum colors and simply block an extra thick outline around the post in gold/yellow?
All you'd need to do is exactly what you're currently doing with CSS and changing the background for FC official posts, and instead change the width and color of the frame surrounding the post instead.
It'll still stick out and be very easy to find, but it won't look so ugly and the contrast will remain the same. (which is easier on the eye balls, since you don't have to adjust your eyes as often).
Also, instead of trying to spell out funcom in a tiny icon in a color that doesn't match anything in the rest of the forum, how about making an icon that looks similar to the ones we can use, but looks like a big FC. We'll get the point without spelling out the entire name, and the color should be something that matches better, like white or gold.
edit! example here!
click me click me click me!