Examine source code of Pale grey

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Pale grey",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(255, 255, 255)",
      "toolbar_text": "rgb(86, 86, 86)",
      "frame": "rgb(242, 242, 242)",
      "tab_background_text": "rgb(134, 134, 134)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(242, 242, 242)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(242, 242, 242)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{cdb7736d-db8d-4bd3-aadf-c7fadc2732ea}"
    }
  }
}