Examine source code of Midnight Black

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Black",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(20, 20, 20)",
      "toolbar_text": "rgb(223, 223, 223)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(220, 220, 220)",
      "toolbar_field": "rgb(0, 0, 0)",
      "toolbar_field_text": "rgb(230, 230, 230)",
      "tab_line": "rgb(89, 89, 89)",
      "popup": "rgb(17, 17, 17)",
      "popup_text": "rgb(220, 220, 220)",
      "popup_border": "rgb(59, 59, 59)",
      "popup_highlight": "rgb(52, 52, 52)",
      "toolbar_field_border_focus": "rgb(59, 59, 59)",
      "tab_loading": "rgb(89, 89, 89)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{68a91f05-26b1-4a1a-9248-e5c159e51a63}"
    }
  }
}