Changing from Redwood Theme to Aquamarine

Summary:

Would changing the theme affect Redwood functionalities?

Content (please ensure you mask any confidential information):

Client would like to change the BG image of the environment, but Redwood theme does not allow it to be changed.

We found that Aquamarine functions similarly to the Redwood theme. We have also tested that the apps that uses the Redwood interface still works as expected.

We would like to know if there are impacts if we change from Redwood Theme to Aquamarine.
Main concern is that there may be some interfaces that will not load or transactions that will not proceed if we did not use the Redwood theme.