Examine source code of classic dark

{
  "theme": {
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#ffffff",
      "button_background_hover": "#5a5a5a",
      "tab_text": "#ffffff",
      "tab_selected": "#5a5a5a",
      "toolbar": "#5a5a5a",
      "icons": "#ffffff",
      "ntp_background": "#373737",
      "ntp_text": "#ffffff"
    }
  },
  "name": "classic dark theme",
  "manifest_version": 2,
  "version": "1.1",
  "description": "This theme was created using Ultimate theme creator"
}