Edit a QR code design

You can edit an existing QR code's design. However, be wary that editing a QR code's design is similar to creating a new one. This is not recommended for QR code that are already published and printed.

In order to edit a QR code design:

Open the QR Codes app.
Right-click the row of the QR code you want to change, then pick Design

The QR code list with a row's contextual menu open, showing Edit, Design, Use this design as template, Export as and Delete

Change the design as you like.
Click on Save.

The same panel can be reached from the QR code's own page.