If you find the default theme limiting in terms of being able to style at a granular level, consider adding this extension.
This is a micro-targeted extension, and focuses solely on category module.
After installing this module, you will see that your category list will have a lot more class, e.g.
<li class="category-menu category-id-133">
<li class="category-menu category-id-38 current">
<li class="category-menu category-id-80 subcategory">
<li class="category-menu category-id-80 subcategory current">
What this means is that:
1. When creating menus, often UI designers and usability guys want the active menu item to look different from others. This is not possible in default theme, but with this module, this becomes possible with CSS.
2. Because each menu item consists a class carrying its category ID, therefore, you can style specific categories in specific ways.
- You can have Eco products category Green, or Summer Products category Yellow, or Watersports category Blue in the category menu/list
- You could put icons alongside specific categories. e.g. "New" or "Sale" icon in Energy Drinks category, or a surfboard icon in Surfboards category, etc.
The point is that this extension provides a great deal of granular control for styling to you.
Because this is a vQmod, no core files are touched, and the changes should carry over to the next version.
Please read documentation!
Support is at http://forum.opencart.com/viewtopic.php?f=131&t=64751
I hope you enjoy this extension. If you'd like to donate, please PayPal at firstname.lastname@example.org