Site Uniformity

[GeoffC]

I have just crashed and burned my old forum and am starting from the ground up with a brand new install of 5.0.1.

I like the default style, more so the background, which I want site wide.

Now I know how to set a page background in HTML, my issue is with my photo galleries made in lightroom which are flash.
When creating a gallery there options to change background colour but not use an image so that option is out, this means changing something in the CSS files but everything I try just ends up back to what lightroom created before upload.

Anyone any advice you can give me on this?

Here is an example link, http://www.nx99.co.uk/photosets/lymepark/
Originally it was all in white as you can see I can change the colour, the blue bit... I want all that and the white at the top the same as the forum background.