[Everlag]

Actually the color inversion is probably a 'filter: invert(100%)' turned on by js; I tried peeking through the DOM and didn't see it, so I may be wrong.

If filter performance is an issue, they could force gpu rendering by applying a 3d transform that does nothing.

[tophtucker]

You're right, lines 104 & 140 in http://www.bloomberg.com/graphics/2015-ketamine-depression-t.... Considered the gpu thing but was reading mixed advice (http://stackoverflow.com/questions/10814178/css-performance-...) and ran out of time.