Examine source code of Minecraft-GTNH

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Minecraft-GTNH",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(163, 169, 240, 0.35)",
      "toolbar_text": "rgba(0, 0, 0, 0.75)",
      "frame": "rgb(55, 91, 102)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgba(79, 83, 136, 0.81)",
      "tab_line": "rgb(73, 73, 202)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(98, 102, 183)",
      "tab_loading": "rgb(73, 73, 202)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b007e8b9-d512-4163-9733-db837e7ef9b7}"
    }
  }
}