Examine source code of Dark Theme Modified

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Theme Modfd",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(43, 42, 51)",
      "toolbar_text": "rgb(251, 251, 254)",
      "frame": "rgb(28, 27, 34)",
      "tab_background_text": "rgb(251, 251, 254)",
      "toolbar_field": "rgb(34, 33, 40)",
      "toolbar_field_text": "rgb(251, 251, 254)",
      "tab_line": "rgb(69, 68, 74)",
      "popup": "rgb(34, 33, 40)",
      "popup_text": "rgb(251, 251, 254)",
      "tab_loading": "rgb(69, 68, 74)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{403ccce9-c823-4e3f-aff3-e7397ae568fa}"
    }
  }
}