Examine source code of green dragon castle

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "green dragon castle",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(37, 44, 70, 0.27)",
      "toolbar_text": "rgb(207, 255, 212)",
      "frame": "rgb(11, 29, 32)",
      "tab_background_text": "rgb(160, 255, 192)",
      "toolbar_field": "rgba(20, 71, 61, 0.52)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(97, 167, 204)",
      "popup": "rgb(11, 29, 32)",
      "popup_text": "rgb(207, 255, 212)",
      "tab_loading": "rgb(97, 167, 204)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{59df6668-ac45-4719-a9f7-e85ad0c4d4e6}"
    }
  }
}