kwimbo , to create a theme you'll need S1fwx, S1res, and any other image editing software.
So firstly, extract your firmware and repair it.
http://www.mympxplayer.org/how-to-ex...tool-vt66.html
Next, using S1res tool, open the repaired firmware and you can view most of the images used in your player.
http://www.mympxplayer.org/how-to-mo...ool-vt206.html
You can always download a modified theme pack and replace the images in your firmware using the import images.
However, if you would like to create your own images, you can use an image editor to create image files of the same dimensions as the original. Then replace the original images with your own.