I took Paradocks' original dark theme and lightened it up a little bit more to my liking. If you'd like to use my lighter version, the script can be found here. Otherwise, Paradocks' original theme can be found here. His also has notes in the script, which may help beginners. The background can of course be changed to another image of your liking, url found near the top of the script.
EDIT: A note that my version also removes the header up top, simply to give the main betting area more screen real estate. It originally also removed the MAX button, but I deleted that line. If you still want the header to show up, just remove that line from the bottom of the script.