ChimeraX only uses a dark theme if you have chosen to use a dark theme for your other applications system-wide.  So one solution would be to chose a light color scheme in your desktop settings. Another solution is to explicitly choose the light theme by starting ChimeraX with the "--color-scheme light" option.  The startup option should be added to the way you invoke ChimeraX, for example by editing the desktop shortcut or by making a (sh/bash/csh/zsh) alias.     -- Greg On 3/22/2025 2:37 AM, jinlun_kylian zhang via ChimeraX-users wrote:

Hi chimeraX developers,

I've used chimeraX for a long time and today I upgraded it to 1.9, But i can't help to notice the chimeraX's theme has been set to dark rather light/white theme in 1.8.

Can you please assist me to modify this dark theme back to white? I am more used to that. image.png

Best, kylian