Customizing Themes

2 minutes to read

Each Segment in a Flex app has an Appearance setting that controls colors, fonts, and spacing for all AppPages in that Segment. You can apply a built-in theme or create a custom theme based on one of the built-in options. Custom themes can be saved and reused across other Segments and apps.

Apply a Built-in Theme

In the Designer, select a Segment in the Segments and AppPages panel.
In the right panel, expand Appearance.
Select a theme from the Theme dropdown.
Select a Variant: Auto, Light, or Dark.

Create a Custom Theme

In the Appearance panel, select Customize next to the Theme dropdown. The theme editor opens.
Use the AppPage dropdown to select a page to preview your changes against.
Use the Mode toggle to switch the preview between Light and Dark.
Adjust the settings as needed.
Select Create to save the custom theme. The theme is applied to the Segment immediately and is available for reuse in other Segments and apps.

Navigate the Theme Editor

The Theme Editor includes a wide range of settings organized into categories such as Colors, Text Styling, Spacing & Sizing, and Panels. Use Search and Filter to quickly find and manage settings.

Search – Enter a keyword to find settings by name.
Filter – Use the filter tabs to narrow the displayed settings:
- General – Shows the most common settings.
- Modified – Shows only settings you’ve changed from the base theme, making it easy to review customizations.
- Mode-specific – Shows only settings with separate values for Light and Dark modes.

Manage Your Themes

Save changes
When editing a custom theme, select Save to apply your changes, or Close to exit without saving.

Restore defaults
Select Restore defaults in the customization panel to remove all modifications and revert the theme to its base built-in settings. This action cannot be undone.

Delete a custom theme
Select Delete to permanently remove the custom theme. Any Segments using the theme automatically revert to the base built-in theme. Deleted themes cannot be recovered.

Reuse Your Themes

Once saved, a custom theme is available in the Theme dropdown for any Segment in the same app or in other apps in your account. Select it the same way you would select a built-in theme.