Fullscreen slider fixed and z-index of color sections

Hi! First of all, I want to congratulate you for such a great theme. It has such a lot of possibilites!
But I’m redesigning my web site and I pursuit some effect I can’t get.
I would like having a fixed fullscreen slider and the rest of the content running over it
Here I’ve the fixed fullscreen slider but if I want a colored background color section for the portfolio part it doesn’t shows. It seems that the color background of the color section goes backyards. First I’ve som text that work fine for me, if I put it with a backgrounded text field. It works fine and I like it! But after that I want to control the background of the portfolio section.

All I want is to control how to put things over that fixed fullscreen slider, and make visible some color backgrounds.
Is it possible?

I don’t know if I’m explaining thing properly, but some great minds probably catch me, don’t them?

Thanks all for your attention!