creating-streamlit-themes

To customize Streamlit app colors and fonts without CSS, edit the .streamlit/config.toml file to define your theme settings. This config-driven approach lets you set primaryColor, backgroundColor, text color, and typography for a cohesive app appearance.

The best way to apply brand colors and typography to a Streamlit app is by configuring the [theme] section in .streamlit/config.toml. You can define light and dark mode variants, chart palettes, and fontFaces served from your app's static path.

Yes, you can use self-hosted fonts in your Streamlit theme configuration by adding fontFaces entries in config.toml. You must serve the custom font files from your app's static path to ensure they load correctly.

To set up light and dark mode variants for Streamlit apps, define separate theme configurations in your .streamlit/config.toml file. This allows you to control backgrounds, text colors, and component styling for consistent UX across both modes.

Yes, Streamlit config.toml theming supports chart and dataframe color palettes. You can tune component styling and define semantic color roles within your theme configuration to maintain consistent data visualization styling.

You should use config.toml for Streamlit theming instead of CSS hacks because it provides a maintainable, config-driven approach. It prevents fragile styling, ensures contrast accessibility guidelines are met, and keeps branding consistent across updates.