In order to remove the background color when using the Design & Print Online software, please follow the steps below.
From Step 3 - Customize:
If a background color was added:
- Click on Background at the top of the project
- Select No Fill
- Click on the Apply button
If a shape with color has been added:
- Click on the Object List button to the right of the screen
- Select the shape from the list that opens
- To the left of the screen, remove the checkmark in the Fill section
If an image has been used as a background please view the article on Making Image Transparent