# Theme

> FullCalendar v3 documentation, for an old release. Web version: https://legacy.fullcalendar.io/v3/theming
>
> Latest version (v7): https://fullcalendar.io/docs/theming.md

It is possible to change the look of the calendar (colors, fonts, etc) by applying a *theme*. Multiple theme systems are available, like Bootstrap and jQuery UI.

## Articles

- [themeSystem](https://legacy.fullcalendar.io/v3/themeSystem.md) - Renders the calendar with a given theme system.
- [themeButtonIcons](https://legacy.fullcalendar.io/v3/themeButtonIcons.md) - Determines which icons are displayed in buttons of the header/footer when jQuery UI theming is on.
- [bootstrapGlyphicons](https://legacy.fullcalendar.io/v3/bootstrapGlyphicons.md) - Determines which icons are displayed in buttons of the header/footer when Bootstrap 3 theming is on.
- [bootstrapFontAwesome](https://legacy.fullcalendar.io/v3/bootstrapFontAwesome.md) - Determines which icons are displayed in buttons of the header/footer when Bootstrap 4 theming is on.

## Demos

- [Bootstrap 4 theme](https://legacy.fullcalendar.io/v3/bootstrap4-theme-demo)
- [jQuery UI theme](https://legacy.fullcalendar.io/v3/jquery-ui-theme-demo)