Customize theme settings

Adjust theme parameters manually when you need a particular visual style. Start from a preset or work with the current settings.

Change a setting

1. Open Preview → Theme.

2. Choose Light or Dark for the variant you are editing.

3. Find the setting you want to change.

4. Adjust it and inspect the relevant elements in Preview.

5. Click Save changes when the result is ready.

Customize theme panel with light and dark modes, typography controls, brand colors, and surfaces

Settings	What to review
Typography	Regular, Heading, and Code fonts; letter spacing
Brand colors	Primary, Secondary, and Accent colors and their text colors
Surfaces	Page, card, popup, muted, and error/destructive backgrounds and text
Borders and focus	Border color, input border, and focus ring
Shapes	Corner radius and spacing

Check the result

Use a page with a table and form. Check body text, headings, input borders, keyboard focus, error text, and button labels. Review the other color mode separately.

For a targeted change, modify one group of settings at a time so you can see its effect. If you do not want to keep unsaved theme edits, use Cancel.

Next: Control app Preview.