How To Highlight Category Posts In Category Page

Hello,

Is it possible to have category pages display what an index page displays (ie. a group of thumbnails for each post). However, when a visitor chooses a category, can the images related to that category be highlighted and have all the other images that are not from that category faded out?

I’ve been searching for plugins and/or tutorials on how I can do this but haven’t found anything yet. Does anyone know of a plugin that does this? Or can I easily implement this in my php pages?

Your help is greatly appreciated?

Antonella