Examine source code of Youtube Dark Interface

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Youtube Dark",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(15, 15, 15)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(15, 15, 15)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(39, 39, 39)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(34, 34, 34)",
      "popup": "rgb(40, 40, 40)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_hover": "rgb(61, 61, 61)",
      "icons_attention": "rgb(255, 0, 0)",
      "ntp_background": "rgb(15, 15, 15)",
      "popup_border": "rgb(40, 40, 40)",
      "popup_highlight": "rgb(61, 61, 61)",
      "sidebar_border": "rgb(40, 40, 40)",
      "sidebar_highlight": "rgb(61, 61, 61)",
      "sidebar": "rgb(40, 40, 40)",
      "tab_loading": "rgb(255, 0, 0)",
      "tab_selected": "rgb(39, 39, 39)",
      "toolbar_bottom_separator": "rgb(15, 15, 15)",
      "toolbar_field_border_focus": "rgb(61, 61, 61)",
      "toolbar_field_border": "rgb(39, 39, 39)",
      "toolbar_field_focus": "rgb(18, 18, 18)",
      "toolbar_field_highlight": "rgb(61, 61, 61)",
      "toolbar_top_separator": "rgb(15, 15, 15)",
      "toolbar_vertical_separator": "rgb(48, 48, 48)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9a7046c7-43ee-4015-9bbf-0c71a15320b6}"
    }
  }
}