Why don’t you just make the images darker and full width?
You can also make the titles in a heavier (bolder) font weight so they display better.
For the little text (normal paragraphs) inside the sections you can chose to do them in something like h3, then you make a white normal section with the long text bellow.
Something like this, may be more easy to read:
http://imgur.com/f1waAYL