What color is this dress: Gold and white or blue and black?

What color is this dress: Gold and white or blue and black?

links to website (to see for yourself):
http://gawker.com/what-color-is-this-goddamn-dress-1688330170
http://mashable.com/2015/02/26/what-color-dress-blue-black-white-gold/
http://www.buzzfeed.com/catesish/help-am-i-going-insane-its-definitely-blue#.qgqayQeBJ
http://www.cnn.com/2015/02/26/us/blue-black-white-gold-dress/