I've been trying to do this with CSS and had some great help from the guys in the CSS forum, but we found out it might be more possible with PHP.
I am using Colorbox, a lightbox JsQuery, to load an external PHP file. Basically, when a user has clicked on a thumbnail image and the page opens up the colorbox, when the user then closes it, I would like the padded background of the thumbnail to be a different color - almost like a 'visited' state (as I say, we tried it with CSS but couldn't get it to work entirely).
Is there some PHP I can assign that says: if div class is clicked, display padded bg color #000000...?
Hope this makes sense!
Thank you and I hope to hear from you!