Please open a project where you wish to change the background colour.

Enter settings of that project (a small Gear button) and pick the background colour of your choice.

Depending on the platform you’re using the Settings section can be located:

  • At the top of your screen (Web, Android);

  • On the right side of the screen (iOS);

  • In the System menu above the Planner 5D window (macOS, Windows).