How to change PyCharm code editor background color?

I would like to change the background color for the PyCharm source code editor. How can I do that?

I am running it under Ubuntu.

Does PyCharm have dark mode?

By default, you can choose between a light, a dark, and a high-contrast theme. You can install other themes as plugins. For more information, see User interface themes. Select this checkbox to let PyCharm detect the current system settings and use the default dark or light theme accordingly.

Providing @Guoliang's helpful comment as a formal answer, as the accepted answer does not answer the question:

Go to Settings > Editor > Colors & Fonts > General

On the right side, expand Text and select Default text

Modify Background as desired.