mootools/mootools-core — pull request #2274 by arian (2012-02-05 04:02:44+00:00)
Title: Fix #2266 - Calling setOpacity with null does not remove the style

See #2266.

Now using `.setStyle('color', null)` actually removes the property, also in IE. It uses the IE only `element.style.removeAttribute` method.