Examine source code of Chromium Dark Mode

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Chromium Dark Mode",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(53, 54, 58)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(60, 64, 67)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(32, 33, 36)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(138, 180, 248)",
      "popup": "rgb(32, 33, 36)",
      "popup_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(138, 180, 248)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c730887d-af69-4309-b8c1-96b4104218a2}"
    }
  }
}