We just developed a firmware tools so people can un package the firmware, and them you can replace the origianl theme, includes fonts, color, icon, and background with your own design.
Please downloda the tools from http://www.filedropper.com/firmwaretools
I hope people can discuss how to DIY the theme and it is quite simple if you just want to replace the background or the fonts. but it may take you a lots of
time to design a full theme files .