Examine source code of Firefox Lineup

{
  "theme": {
    "images": {
      "theme_frame": "FirefoxHeader.png"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#ff9830"
    }
  },
  "version": "2.0",
  "name": "Firefox Lineup",
  "manifest_version": 2,
  "description": "Firefox is part of an art challenge and was painted from scratch using TwistedBrush."
}