Examine source code of Gnome Colors

{
  "name": "Gnome Colors",
  "author": "Matteo Nista",
  "manifest_version": 2,
  "version": "1.1",
  "theme": {
    "colors": {
      "frame": "rgba(40, 40, 40, 1)",
      "frame_inactive": "rgba(40, 40, 40, 1)",
      "tab_text": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(170, 170, 170, 1)",
      "tab_line": "rgba(21, 83, 158, 1)",
      "tab_loading": "rgba(21, 83, 158, 1)",
      "toolbar": "rgba(40, 40, 40, 1)",
      "toolbar_top_separator": "rgba(40, 40, 40, 1)",
      "toolbar_bottom_separator": "rgba(40, 40, 40, 1)",
      "toolbar_vertical_separator": "rgba(40, 40, 40, 1)",
      "toolbar_field": "rgba(18, 18, 18, 1)",
      "toolbar_field_text": "rgba(200, 200, 200, 1)",
      "toolbar_field_border": "rgba(18, 18, 18, 1)",
      "toolbar_field_separator": "rgba(18, 18, 18, 0.2)",
      "toolbar_field_focus": "rgba(18, 18, 18, 1)",
      "toolbar_field_border_focus": "rgba(18, 18, 18, 1)",
      "button_background_hover": "rgba(255, 255, 255, 0.12)",
      "button_background_active": "rgba(255, 255, 255, 0.15)",
      "bookmark_text": "rgba(170, 170, 170, 1)",
      "popup": "rgba(40, 40, 40, 1)",
      "popup_text": "rgba(200, 200, 200, 1)",
      "popup_border": "rgba(40, 40, 40, 1)",
      "popup_highlight": "rgba(255, 255, 255, 0.15)",
      "popup_highlight_text": "rgba(255, 255, 255, 1)",
      "ntp_background": "rgba(45, 45, 45, 1)",
      "ntp_text": "rgba(170, 170, 170, 1)",
      "sidebar": "rgba(40, 40, 40, 1)",
      "sidebar_text": "rgba(170, 170, 170, 1)",
      "sidebar_border": "rgba(40, 40, 40, 1)",
      "sidebar_highlight": "rgba(255, 255, 255, 0.15)",
      "sidebar_highlight_text": "rgba(170, 170, 170, 1)"
    }
  }
}