Hallo Stiggi,
Very cool and nicely written plugin
Congrats, and many thanks for sharing your work with the community
I like the way you designed and implemented this plugin, the use of an XML file, the use of the CSS parser, the optimized profile display with pre-computed CSS user file, the clean installer, the cool JS color picker. Some nice concepts
Special mention for doing this using the CB API without any hacks (from what I have seen so far).
One minor feedback on your demo: the JS color picker works fine in Firefox but doesn't run with latest Safari 2.0.4: i see JS error Object (result of expression attachColorPicker) does not allow calls. on loading edit profile page.
And one suggestion (in addition of Mikko's): the user-interface on edit profile could look less "technical" and hide some of the technical details from the first user view. The technical details like css attribute and class names could be hidden completely or in "i" infos.
Kudos !