It's possible to customize almost every aspect of your flow variant in the Style tab.
The easiest way to get a sense for this is to open the live preview window and see your changes take effect on your real flow. For this reason, we recommend fleshing out at least some of the steps and questions before trying to get the styling perfect.
When you publish a style set as a theme, it can be re-used in any flow in your organization. To save the current set of styles as a theme, click Edit... on the top-roght of the style editor tab.
Changes made to a variant sit on top of the base theme - you may revert any change made by hovering that particular setting and clicking Revert.