How to change the color of customer interface tab?

Hello @shirley huang,

You can make use of the Link color > Link text option under Admin > Portals > Customize portal to change the color of  New support ticket and Check ticket status options. In case you trying to change the background of these options, you can make use of the Background color > Help center option. In any case, the changes would reflect in all the applicable sections of the customer portal. 

Also, we recommend you to save the changes and preview before publishing it for the customers. Feel free to drop a note here for any further queries! :)

Cheers,

Freshworks Community Team