Examine source code of Green Screen

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Green Screen",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(151, 219, 177)",
      "toolbar_text": "rgb(0, 0, 0)",
      "frame": "rgb(29, 140, 70)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(227, 240, 231)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(39, 132, 73)",
      "popup": "rgb(150, 219, 177)",
      "popup_text": "rgb(0, 0, 0)",
      "icons_attention": "rgb(24, 16, 64)",
      "ntp_background": "rgb(83, 191, 127)",
      "sidebar": "rgb(29, 140, 70)",
      "toolbar_vertical_separator": "rgb(22, 14, 57)",
      "tab_loading": "rgb(39, 132, 73)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{bfef5cd3-ec19-460d-89d0-f68d4fcc3df6}"
    }
  }
}