Animation can also show changes in size or in color. The YUI library provides functions for making gradual changes, one of which, YAHOO.util.ColorAnim, will be used in the following pages. For example, maybe you want to show the users that changes have been made to the page since they first loaded it. A blue box could become a red one to warn them.

Click on the box to see it change colors.

Gradual changes like this make it easy to get users' attention.