I recently installed WP with the Kubric theme. The theme is clean and neat but I'd like to change the blue "banner" to something more site specific. I've googled, etc. for methods but some seem rather dated and others seem to be ineffective when I try the method(s) described. Of course, it's possible I am doing something wrong, or mis-understanding. What is the simplest method of replacing the blue banner? If I need to create a new image I have GIMP and PS Elements 6 on hand.