Just curious, but why don't you use real transparency? Not everyone uses the same colors for the site background, so your solution isn't optimal.
by which i mean print screen the text select the backdrop colour and put it as the background to my art faking transparency
The plain colored backgrounds I've noticed with all of your work in the queue don't seem to add anything with the pictures. I would consider replacing them with transparency. If you need help with that there's a link to an FAQ in the guidlines section that shows up when submitting a piece.
cause i only use paint