Examine source code of Splatoon 3 (Team Future)

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Splatoon 3 (Team Future)",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "left top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(128, 128, 128)",
      "toolbar_text": "rgb(220, 255, 81)",
      "frame": "rgb(220, 255, 81)",
      "tab_background_text": "rgb(128, 128, 128)",
      "toolbar_field": "rgb(115, 247, 51)",
      "toolbar_field_text": "rgb(128, 128, 128)",
      "tab_line": "rgb(115, 247, 51)",
      "popup": "rgb(128, 128, 128)",
      "popup_text": "rgb(220, 255, 81)",
      "tab_loading": "rgb(115, 247, 51)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{e4ec67c6-9ec2-4d6e-9681-35c9bde6fe6a}"
    }
  }
}