Examine source code of Plain Gray

{
  "theme": {
    "images": {
      "theme_frame": "gray.jpg"
    },
    "colors": {
      "frame": "#f0e4e4",
      "tab_background_text": "#f2eaea"
    }
  },
  "version": "2.0",
  "name": "Plain Gray",
  "manifest_version": 2
}