User interface themes
The interface theme defines the appearance of windows, dialogs, buttons, and all visual elements of the user interface.
Change the UI theme
In the Settings/Preferences dialog Ctrl+Alt+S, select Appearance & Behavior | Appearance.
Select the UI theme from the Theme list:
There are a number of themes that you can choose depending on your taste and experience with other IDEs. If JetBrains Rider is your first IDE, we suggest one of the following themes:
Rider Light: Default light theme
Rider Light: Default dark theme
High contrast: Theme designed for users with color vision deficiency
It is also possible to create your own UI themes for JetBrains Rider and customize the built-in themes. For more information, see IntelliJ Platform SDK Documentation.