I've used firebug to play around with the colours on the free template I'm using (photoria).
I put all the code for each amend into the custom.css file in the edit themes section of wordpress.
As far as i can tell from this tutorial,
http://www.wpzoom.com/tutorial/how-to-customize-a-wpzoom-theme/, there should be a button at the bottom that says 'update file'
but I don't have this.
Any idea how I can get my custom colours to work?