Examine source code of Snow covered tree

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Snow covered tree",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg",
        "images/1.jpg",
        "images/2.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center",
        "right center",
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "repeat",
        "repeat",
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(236, 220, 249)",
      "toolbar_text": "rgb(159, 65, 190)",
      "frame": "rgb(223, 182, 246)",
      "tab_background_text": "rgb(159, 65, 190)",
      "toolbar_field": "rgba(255, 255, 255, 0)",
      "toolbar_field_text": "rgb(159, 65, 190)",
      "tab_line": "rgb(253, 124, 73)",
      "popup": "rgb(236, 220, 249)",
      "popup_text": "rgb(159, 65, 190)",
      "tab_loading": "rgb(253, 124, 73)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{77461e6a-3d8c-4f35-b4ce-2bbe97158034}"
    }
  }
}