Transparent background within header area?

Hi Guys,

I've been trying to make a module assigned to the header position transparent so that the background image of the website shows through. However, when I change the gkHeader background to transparent, it turns white instead. It's as if there is something else behind it that is solid white. I've tried numerous changes overriding the CSS but none seem to make the background transparent. It's also the same for the navigation along the top. I want the backgrounds to the top menu items to be transparent so that the background image is shown behind. I'm sure it's something simply that I'm missing!" Any help would be appreciated.
Many thanks!

D

Hi,

Can I have your site link to take a look?