I posted about Elegance Colors before. It is a chameleon theme for Gnome Shell which can change colors according to the current GTK theme, current wallpaper (uses imagemagick to get color) or a user defined color. Today I have updated it with some new features (and bug fixes too). The most notable feature is that it allows to export your customized theme. So you can basically create a new Gnome Shell theme! You can theoretically create an unlimited number of themes with different customization settings. Though it is not the same as making your own Gnome Shell theme by hand, it is still an easy way to make themes with customized colors, gradients, transparency etc. Don’t expect your theme to be unique though!