Examine source code of Mugen I

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Gab",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-001-9c6d74e14860e77ee6f8f43e824bff25.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(142, 179, 201)",
      "toolbar_text": "rgb(98, 102, 183)",
      "frame": "rgb(98, 102, 183)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(77, 79, 121)",
      "tab_line": "rgb(142, 179, 201)",
      "popup": "rgb(77, 79, 121)",
      "popup_text": "rgb(255, 255, 255)",
      "icons": "rgb(77, 79, 121)",
      "tab_selected": "rgb(77, 79, 121)",
      "tab_text": "rgb(255, 255, 255)",
      "toolbar_field_border_focus": "rgb(142, 179, 201)",
      "toolbar_field_border": "rgb(77, 79, 121)",
      "toolbar_field_text_focus": "rgb(98, 102, 183)",
      "tab_loading": "rgb(142, 179, 201)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{45d0edf8-e4bf-43c2-8c8e-f655c752a84e}"
    }
  }
}