For anyone else who wants to know about this! it seems it can be done!
I did the following
1. Copied the styles from 4images/templates/default/style.css and added them to the end of my individual themes css files.
2. Deleted the css file in 4images/templates/default/
3. then edited the entries I pasted in the individual theme css files!
I guess by removing 4images css file, it defaults to the css file contained in the geeklog header!
Dazzy