Examine source code of skeet.cc solution

{
  "name": "gamesense",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "sasanse.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(133, 184, 51, 1)",
      "toolbar": "rgba(20, 20, 20, 1)",
      "bookmark_text": "rgba(128, 128, 128, 1)",
      "toolbar_field": "rgba(20, 20, 20, 1)",
      "toolbar_field_text": "rgba(120, 158, 32, 1)",
      "tab_line": "rgba(139, 176, 81, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1e3cd1ea-cd1f-4bf9-ae3a-e77cb6e0f2b3}"
    }
  }
}