8 of 12 Refactor question to be on-topic and cite notable claims as per the buzzfeed article. Apologies to the OP for trimming their content :)

Is this dress blue and black in colour?

Buzzfeed, and other social media, are buzzing about this image: Magic Dress

When I see this image, I can only see a gold and white dress. However, others claim that the dress is actually black and blue in colour. Going by the Buzzfeed survey (as unreliable as it might be), 70% of users viewing the image believe it to be gold and white while 30% believe otherwise. Some people (also see the comments to this question) find that the dress changes colour for them. Is the dress really black and blue in colour? Why does the apparent majority then perceive it to be gold and white? If it's an optical illusion, how can the same person perceive the same image differently at different times?