Examine source code of Dark Theme

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Dark Theme",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(128, 128, 128)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(25, 25, 25)",
      "tab_background_text": "rgb(214, 214, 214)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(235, 235, 235)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(235, 235, 235)",
      "toolbar_field_highlight": "rgba(0, 120, 215, 1)",
      "toolbar_field_highlight_text": "rgba(255, 255, 255, 1)"
    }
  }
}