How to design Zappy Upsell Funnels to match your store's theme? 1. Open the 'Customize' tab to customize everything related to the Upsell Funnel. 2. Modify everything, right from the Widget Texts to the Theme Colours. All of your changes can be previewed live on the preview widget on the right-hand side of your screen. 3. Click Save to save the changes or Reset to Default to start over.