Clone / duplicate a Style Kit
You can clone any Style Kit and create a duplicate of it, in cases where you want to customise any of the Styles without affecting your current Kit. In earlier versions of Style Kits, the clone function was referred to as Save As...
Cloning your Style Kit
To clone the Style Kit you are working on, go to Theme Styles and open the Style Kits tab. Then, at the bottom you will find the "Manage Style Kit" panel.
Once the panel is expanded, click on the Clone Style Kit button.
In the popup, give your new Style Kit a name and click Save. Your New Style Kit will be saved and applied on the specific page.
Your new cloned Style Kit will be applied on the page and you should be able to customise it as you see fit. Enjoy!