1. Go to your report, and select design in the side menu (if the side menu is not open click on the report menu icon  to open it first).
2. Click on edit* above the report's colour theme.
3. Click on the colour theme you want to delete and choose select. If you want to select all the colour themes, click on the select all icon ().
4. Click on the delete icon (). The selected colour themes will be deleted immediately.

* Feature is only available with a Professional subscription. View our plans and pricing.