twitter/bootstrap — pull request #4055 by Marmelatze (2012-07-10 17:35:24+00:00)
Title: Fixes vertical-three-colors in Firefox

The less mixin for vertical-three-colors doesn't seem to work in Firefox 13.0.1.
It just displays the default background-image option. It looks like Firefox want a percentage value.

I hope `*100%` works fine.