gold white-or blue black dress

Internet can be such a weird place. So today it seems that the most important question on entire internet is : is the dress on the photo blue and black or is it gold and white. The world has divided into 2 groups, celebrities are tweeting about it, news portals are writing about it. The dress is tearing us all apart! So what is it? Can you tell us? Is it blue and black or is it gold and white?