In this tutorial you will learn how to change BurpSuite's default white theme to dark theme.
1)Launch BurpSuite and Go to Settings
Click the settings button as shown in the image below

2) Go to User Interface and then to Display
Once you open settings window, click to user interface

and then click to Display

3) Select Dark on Appearance Section
Check the Dark box on this section and the dark theme will get applied immediately to BurpSuite, so you don't need to relaunch the software manually.

How to fix Theme gets reverted back to white issue
If for some reason the dark theme won't be enabled automatically next time you run Burp you need to save your settings configuration. This option allows you to export a config json file that contains all your current configurations.
So if theme or any other setting changes you can simply upload user settings and you will have the same settings enabled again on your BurpSuite
To export user settings, go to Settings >> Manage Global Settings >> User settings >> Save User Settings and choose the location where you want to save the configuration file

Conclusion
In this tutorial you learned how to activate dark mode on BurpSuite on Linux mint. Even though this tutorial was made in Linux mint 21, steps to follow should be the same for other Linux distros.