How can I put a background image to the search bar's rectangle area?

Hi James,

Welcome to the Freshworks Community!

I understand you are looking to update your portal theme, please feel free to take a look at the available themes from the following link -

https://community.freshworks.com/freshthemes-gallery-11001

And, about adding a background image to the search-bar, this can be achieved using portal customization, you can customize your portals to the desired look.

Please refer to the following link, for further insight into this -

https://support.freshdesk.com/en/support/solutions/articles/50000003753-customizing-your-customer-portal

I hope this helps, do let me know, if you have any further issues and I will be happy to help! :)

Cheers!