Examine source code of Serenity Firefox Theme

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#ffffff",
      "tab_background_text": "#000000"
    }
  },
  "version": "2.0",
  "name": "Serenity Firefox Theme",
  "manifest_version": 2,
  "description": "A theme that uses a soft blue color as a background with the new Firefox Theme (as of 19/08/2013) in its top left. For some reason I really like this new logo and (after already creating a wallpaper) I decided to create a theme."
}