Themes and customization

Open Settings > Themes to search Relay's built-in themes by name or category and preview one before applying it.

You can export the active theme as CSS, import a theme CSS file, or add custom CSS overrides. Treat imported CSS as code: use themes only from sources you trust, and check customizations after a Relay update because interface selectors can change.

Instance administrators choose the default theme and can add authentication/sidebar branding under Integrations and branding.