Examine source code of Plain And Simple Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Total Dark",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(26, 26, 26)",
      "toolbar_text": "rgb(238, 238, 238)",
      "frame": "rgb(16, 16, 16)",
      "tab_background_text": "rgb(204, 204, 204)",
      "toolbar_field": "rgb(16, 16, 16)",
      "toolbar_field_text": "rgb(238, 238, 238)",
      "tab_line": "rgb(30, 30, 30)",
      "popup": "rgb(30, 30, 30)",
      "popup_text": "rgb(238, 238, 238)",
      "tab_loading": "rgb(30, 30, 30)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{19fbca14-905c-471b-80b7-e07a093ce961}"
    }
  }
}