Examine source code of new_firefox

{
  "theme": {
    "images": {
      "theme_frame": "firefoxlogoneu.JPG"
    },
    "colors": {
      "frame": "#6e6363",
      "tab_background_text": "#050505"
    }
  },
  "version": "2.0",
  "name": "new_firefox",
  "manifest_version": 2,
  "description": "firefox mozilla fuchs feuer"
}