CSS3 has a new filter attribute which will only work in webkit browsers supported in webkit browsers and in Firefox. It does not have support in IE or Opera mini:
img {_x000D_
-webkit-filter: invert(1);_x000D_
filter: invert(1);_x000D_
}
_x000D_
<img src="http://i.imgur.com/1H91A5Y.png">
_x000D_