QT Designer Theme

[itsgoodforyou2]

Hello, I am studying various ways to make Python UI through your YouTube. One question is why the theme color of the Qt Designer you use and the Qt Designer I use is different. For example, what I'm using is a bright color, and what you're using is a dark color. Especially, the main window color I use is gray, but the one you use is dark, and the finished UI is also made nice with dark colors. How can I produce UI with dark colors like you?

[spyhabs]

Change the linux - ubuntu settings in dark mode.