Examine source code of Rocketverse Adventure

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Rocketverse Adventure",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(7, 50, 84, 0)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(48, 2, 48)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(252, 238, 244)",
      "toolbar_field_text": "rgb(67, 3, 90)",
      "tab_line": "rgb(4, 2, 4)",
      "popup": "rgb(39, 1, 62)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(4, 2, 4)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d1c36e3a-9389-421d-8edc-0143bf53b47a}"
    }
  }
}