Category Styling Problem

Okay, so I’m using the newest ifeature free theme. My question/problem is, however, more universal than that.

I’m trying to have different styling for different categories.

In my theme I have core action php file called index-actions.php which I’ve tried to edit. See https://github.com/cyberchimps/iFeature/blob/master/core/actions/index-actions.php

(Let us say I have a post category called “12345”) Now what I’ve done is that I’ve added php script to different parts of file but the idea is to:

<?php if ( in_category( '12345' )) {
	^*then don't synapse loop, don't how to do it*^
} else {

}synapse_loop(); ?>

I know this probably isn’t the smartest way to do the categorization, but this should work in my case. Other solutions are also welcome if they’re understandable 😉

And, yes I have read about loop and categorization but I just don’t get it.