Examine source code of Plane-Sandy

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Sandy",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-001-9c6d74e14860e77ee6f8f43e824bff25.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(142, 133, 95)",
      "toolbar_text": "rgb(30, 29, 24)",
      "frame": "rgb(41, 41, 30)",
      "tab_background_text": "rgb(142, 133, 95)",
      "toolbar_field": "rgb(218, 213, 186)",
      "toolbar_field_text": "rgb(30, 29, 24)",
      "tab_line": "rgb(232, 183, 0)",
      "popup": "rgb(38, 35, 19)",
      "popup_text": "rgb(215, 190, 60)",
      "button_background_hover": "rgb(63, 58, 36)",
      "icons_attention": "rgb(255, 201, 0)",
      "icons": "rgb(255, 206, 0)",
      "tab_loading": "rgb(232, 183, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{44123639-4040-466e-bb1d-70c675b097f3}"
    }
  }
}