GeoGebra uses webtchnology (html, css, js) and thus can be customized without recompiling ==== Add custom Darkmode ==== Open the file

Windows:

C:\Users\User Name\AppData\Local\GeoGebra_6\app-6.0.683\resources\app\html\classic.html

and change the line (873)

<body dir="ltr" tabindex="-1" onload="loadApp()">

<body dir="ltr" tabindex="-1" onload="loadApp()" style="filter: invert();">