Our company hired an outside developer to make changes to our WordPress header and theme colors. After he made the changes, we attempted to update the logo and change the header menu font color by using the built in appearance theme customizer, but this caused the changes to reset back to their previous form. (We have the Cherry framework.) We really don't want to have to hire a developer every time we'd like to make a small change.
The closest information I have been able to find is relating to creating child themes in order to keep customizations after updates.
Is it possible or what is the best way to make custom CSS changes and still be able to use the built in theme customizer?