Examine source code of Simple Color Red

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple Red",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-037-b73f9b34467ba541de861f5b4c0c6316.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(91, 17, 0)",
      "toolbar_text": "rgb(253, 253, 253)",
      "frame": "rgb(153, 0, 0)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(64, 2, 2)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(255, 0, 57)",
      "popup": "rgb(62, 0, 2)",
      "popup_text": "rgb(248, 248, 251)",
      "toolbar_bottom_separator": "rgb(117, 1, 7)",
      "toolbar_field_border_focus": "rgb(165, 2, 8)",
      "toolbar_field_border": "rgb(130, 0, 6)",
      "toolbar_top_separator": "rgb(130, 0, 6)",
      "tab_loading": "rgb(255, 0, 57)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{827b0819-8dea-4bf9-b675-f34530a7bfec}"
    }
  }
}