Is there a way to change the heading bar?

I am really liking the Lightning theme. On each page (except the home page)there is a colored bar across the top with the page title on it. I was wondering if there was a way to change the colored heading bar to an image. I would like the image to be the same size as the bar. Thank you for any help you can offer.

The page I need help with: [log in to see the link]