Colored Icons front page

Hello!
First of all, congratulations on such a great free theme. I will be reviewing it in a few days after I’ve had more time to try it out, but I believe it will be a very good rating!

I am finding problems to edit the so-called “overlapable” section icons. In reality, I don’t know why, in my website they don’t appear as “icons”, but only as 4 colored balls. ??
I don’t seem to be able to edit them at all. I clic on the edit button and the ball just turns to black and back to original color again. I can do nothing.

I would like to add an icon, to change colors and also, is it possible to substitute them for images? Just a question.

Thanks for your help in advance.

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