Updating Customized Theme

Hi Sakin: I just updated WordPress and now want to update CatchEvolutionPro. Issue is what to do with the customization. I copied that to a separate file out in case I lost it, but am confused as to what will happen if I update to the latest CatchEvolutionPro from 1.6. I cannot even figure out where the customization is stored. It seems not to be in Styles.css. You have a comment that it is in a database. What is that database and what is its name? I also note a button on the CatchEvolutionPro when I show themes - it says customize. Not reall sure what to do to preserve my customization.