Yes, but I think I´ve figured it out.
In case someone else wants to know:
I created a new child theme called CATEGORY NAME and replaced the 3 images from the background of the theme.
At the nodes tree, I chose to override the theme in the node NAME and changed it to CATEGORY NAME.
It works for me if you are aware of any draw backs from this please do let me know.
We are really liking your theme, thanks for making it.