First, I have to say I'm in love with this theme. Extremely well done, and I've been able to find answers most of my questions already between WP support and your website. I will probably end up upgrading to Pro in the near future (I want that Portfolio feature!).
Now then, my question is similar to this one, but I wasn't able to resolve it with the advice in that thread.
All of my uploaded images have an 8px blue-gray bar on the bottom (see http://fionapayne.info. I want to do two things: change the color of this bar on some images, and eliminate it completely on others. Can you explain further how to edit this bar on selected images? FWIW, I'm familiar with html basics but new to editing CSS.