Examine source code of Everything Dark Clean

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Everything Dark Clean",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(33, 33, 33)",
      "toolbar_text": "rgb(214, 214, 214)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(214, 214, 214)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(238, 238, 238)",
      "tab_line": "rgb(117, 117, 117)",
      "popup": "rgb(33, 33, 33)",
      "popup_text": "rgb(214, 214, 214)",
      "popup_highlight": "rgba(64, 64, 64, 0.74)",
      "toolbar_field_border_focus": "rgb(68, 68, 68)",
      "toolbar_field_border": "rgb(79, 79, 79)",
      "toolbar_field_highlight": "rgba(158, 158, 158, 0.41)",
      "toolbar_vertical_separator": "rgb(120, 120, 120)",
      "tab_loading": "rgb(117, 117, 117)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{d8492dc0-2758-44ef-a611-2b559985b122}"
    }
  }
}