On the right of the environment's details page, click Edit Environment and then Customize Viewer.
The Customize Environment Viewer page appears.
To change the basic settings, select Custom Settings from the Apply settings from dropdown.
The basic settings are now editable.
To access advanced settings, click Switch to Advanced Mode.
When you're done making changes, click Save. This saves your customizations to the environment.
If your environment was created from a blueprint, you can apply your customizations to the snapshot from which it was created. To do that, select Apply viewer settings to snapshot and then click Save.
Keep in mind that applying changes to the snapshot will affect all currently active environments, as well as any environments that are created from that snapshot in the future.