Examine source code of Midnight

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Midnight",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(46, 49, 56)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(30, 48, 86)",
      "tab_background_text": "rgb(215, 226, 239)",
      "toolbar_field": "rgb(46, 49, 56)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(46, 49, 56)",
      "popup": "rgb(31, 34, 61)",
      "popup_text": "rgb(215, 226, 239)",
      "tab_loading": "rgb(46, 49, 56)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{326d8103-23c6-4b8d-856f-fddbfc322595}"
    }
  }
}