Examine source code of Simple Work Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Simple Dark",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(0, 0, 0)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(164, 164, 164)",
      "toolbar_field": "rgb(217, 217, 217)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(217, 217, 217)",
      "popup": "rgb(217, 217, 217)",
      "popup_text": "rgb(0, 0, 0)",
      "popup_border": "rgb(0, 0, 0)",
      "tab_selected": "rgb(217, 217, 217)",
      "tab_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(217, 217, 217)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{a8367a7d-c768-4827-bf28-8bf367c08190}"
    }
  }
}