1. Choose Edit > Dashes and Stripes.
2. Create a new Dash named "taste the rainbow" (make sure it is in written in lowercase - with no quotes either).
3. Click Save.
4. The Style sheet menu is now shown in bands of color.
5. With the content tool selected, inside a text box - this makes the style sheet menu active - press Command-Option-Shift and click a style sheet.
It is more interesting when you have plenty of style sheets.
6. For more, go into the Paragraph Formats menu, and other field menus and see what happens.
This is only available in QuarkXPress 4.