These docs are for an old release.
Info on upgrading to v4
theme
Enables/disables use of jQuery UI theming.
This setting has been deprecated. To use jQuery UI theming, set the themeSystem setting to
'jquery-ui' instead.
Boolean, default: false
Once you enable theming with true, you still need to include the CSS file for the
theme you want. For example, if you just downloaded a theme from the
jQuery UI Themeroller, you need to put a <link>
tag in your page’s <head>.