Examine source code of Simple Red

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple Red",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-036-40a272fe657f748396e017c7a64ee2dc.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(196, 9, 9)",
      "toolbar_text": "rgb(255, 0, 0)",
      "frame": "rgb(29, 23, 23)",
      "tab_background_text": "rgb(188, 40, 40)",
      "toolbar_field": "rgb(70, 68, 68)",
      "toolbar_field_text": "rgb(188, 40, 40)",
      "tab_line": "rgb(196, 9, 9)",
      "popup": "rgb(55, 54, 54)",
      "popup_text": "rgb(255, 0, 0)",
      "button_background_hover": "rgb(42, 0, 244)",
      "tab_loading": "rgb(196, 9, 9)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{8a117d94-12a7-479e-a023-f677ca7fd954}"
    }
  }
}