Presentation Demo – How do I make my header translucent?

I am referring to the Highend Theme with the “Presentation” demo. The header within the Presentation demo is translucent, allowing the background image to show through. I have tried to copy all of the settings within the demo and apply them to my site. Unfortunately, I have not been able to achieve the same effect. My header background continues to be solid white, with the presentation images below. Please advise.

Thanks in advance.