Examine source code of blue skies

{
  "name": "blue skies",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "theme3.jpg"
    },
    "colors": {
      "frame": "rgba(120, 132, 158, 1)",
      "tab_background_text": "rgba(121, 130, 191, 1)",
      "toolbar": "rgba(230, 225, 205, 0.46)",
      "bookmark_text": "rgba(194, 191, 165, 1)",
      "toolbar_field": "rgba(240, 226, 183, 0.73)",
      "toolbar_field_text": "rgba(255, 251, 214, 1)",
      "tab_line": "rgba(245, 240, 226, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{11066628-2df4-442e-bc10-9c90816e384c}"
    }
  }
}