Change web page back ground and logo - Can this be done if you are a OCS Customer

Our instance of JDE is hosted by Oracle Cloud Services. We, like many others would like to change the screen colors of our lower environments. I've found the many post on how to do it. My CNC group is telling me we can't do it because OCS will just change it back to their settings.

I'm looking for feedback from an OCS customer that has changed either the logo or screen backgrounds.