Just got around to trying it I think you must have made a change to writing the theme file.
Traceback (most recent call last):
File "./sublime_plugin.py", line 143, in on_modified
File "./css-colors.py", line 378, in on_modified
File "./css-colors.py", line 306, in colorize_css
File "./css-colors.py", line 261, in generate_color_theme
File "/System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/plistlib.py", line 75, in readPlist
pathOrFile = open(pathOrFile)
IOError: [Errno 2] No such file or directory: u'/Users/facelessuser/Library/Application Support/Sublime Text 2/Packages/User/Colorized-766606182254614-Monokai Soda.tmTheme'
This causes the colors to all be white since it looks like it is failing to write the theme file.