This customization gives you the freedom to alter design changes on the tenant portal (Customer Portal).

To do so, click on the Admin icon on the left sidebar menu.

Then click on Customization tab and click on Design Changes 

There are 3 categories: Login Page and Find Storage. Here you can edit color changes as required. Then click on Save & Preview.

The Save & Preview option gives you a preview of the customer portal on a new tab.

Similarly, changes you make on (Find Storage) is affected on customer portal

Also, changes you make on (Customer portal move in page) is affected on customer portal

Related: Want to update unit pictures in bulk?