Examine source code of Dark L20 Grey

{
  "manifest_version": 2,
  "name": "Dark L20 Grey",
  "version": "1.0",
  "description": "A simple dark theme with grey colour scheme.",
  "author": "W5nH6o",
  "theme": {
    "colors": {
      "frame": "rgb(20, 20, 20)",
      "frame_inactive": "rgb(31, 31, 31)",
      "toolbar": "rgb(51, 51, 51)",
      "tab_text": "rgb(229, 229, 229)",
      "tab_background_text": "rgb(177, 177, 179)",
      "bookmark_text": "rgb(229, 229, 229)",
      "ntp_background": "rgb(20, 20, 20)",
      "ntp_text": "rgb(190, 190, 190)",
      "tab_line": "rgb(51, 51, 51)",
      "toolbar_field": "rgb(20, 20, 20)",
      "toolbar_field_focus": "rgb(13, 13, 13)",
      "toolbar_field_text": "rgb(229, 229, 229)",
      "popup": "rgb(31, 31, 31)",
      "popup_border": "rgb(51, 51, 51)",
      "popup_text": "rgb(229, 229, 229)",
      "sidebar": "rgb(31, 31, 31)",
      "sidebar_border": "rgb(51, 51, 51)",
      "sidebar_text": "rgb(229, 229, 229)"
    }
  }
}