Examine source code of Hedgehog Night

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Hedgehog Night",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center",
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat",
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(25, 43, 69, 0.35)",
      "toolbar_text": "rgb(215, 235, 255)",
      "frame": "rgb(0, 6, 94)",
      "tab_background_text": "rgb(191, 113, 197)",
      "toolbar_field": "rgba(34, 4, 41, 0.34)",
      "toolbar_field_text": "rgb(215, 243, 255)",
      "tab_line": "rgba(32, 133, 205, 0.44)",
      "popup": "rgb(0, 2, 27)",
      "popup_text": "rgb(216, 148, 231)",
      "button_background_hover": "rgb(60, 41, 151)",
      "tab_loading": "rgba(32, 133, 205, 0.44)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2dae16ad-843d-4e19-b5d2-d120cea37d1a}"
    }
  }
}