Examine source code of Great Grey

{
  "name": "Great Grey",
  "author": "Arif Waqas",
  "manifest_version": 2,
  "version": "2020.6.30",
  "theme": {
    "colors": {
      "frame": "rgba(0, 0, 0)",
      "frame_inactive": "rgb(0, 0, 0)",
      "tab_text": "rgb(255, 255, 255)",
      "tab_background_text": "rgb(170, 170, 170)",
      "tab_line": "rgb(35, 35, 35)",
      "tab_loading": "rgb(211, 211, 211)",
      "toolbar": "rgb(35, 35, 35)",
      "toolbar_top_separator": "rgb(35, 35, 35)",
      "toolbar_bottom_separator": "rgb(35, 35, 35)",
      "toolbar_vertical_separator": "rgb(35, 35, 35)",
      "toolbar_field": "rgb(18, 18, 18)",
      "toolbar_field_text": "rgb(200, 200, 200)",
      "toolbar_field_border": "rgb(18, 18, 18)",
      "toolbar_field_separator": "rgba(18, 18, 18, 0.2)",
      "toolbar_field_focus": "rgb(18, 18, 18)",
      "toolbar_field_border_focus": "rgb(30, 30, 30)",
      "button_background_hover": "rgba(200, 200, 200, 0.12)",
      "button_background_active": "rgba(255, 255, 255, 0.15)",
      "icons": "rgb(169, 169, 169)",
      "bookmark_text": "rgb(170, 170, 170)",
      "popup": "rgb(18, 18, 18)",
      "popup_text": "rgb(200, 200, 200)",
      "popup_border": "rgb(18, 18, 18)",
      "popup_highlight": "#21252B",
      "popup_highlight_text": "rgb(255, 255, 255)",
      "ntp_background": "rgb(18, 18, 18)",
      "ntp_text": "rgb(170, 170, 170)",
      "sidebar": "rgb(35, 35, 35)",
      "sidebar_text": "rgb(170, 170, 170)",
      "sidebar_border": "rgb(18, 18, 18)",
      "sidebar_highlight": "#21252B",
      "sidebar_highlight_text": "rgb(170, 170, 170)"
    }
  }
}