Install color themes for emacs on ubuntu

1. sudo apt-get install emacs-goodies-el
2. Start emacs, use M-x color-theme-select to select theme
3. Select a theme and press "Enter" to preview it. If you want to use it, press "D", another frame will appear. Find (color-theme-xxx) and add it to your .emacs.
4. Don't forget to add (require 'color-theme) too.