The dress

The phenomenon revealed differences in human colour perception and became the subject of scientific investigations into neuroscience and vision science.

The retailer of the dress, Roman Originals, reported a surge in sales and produced a one-off version in white and gold sold for charity.

In February 2015, about a week before the wedding of Grace and Keir Johnston, of Colonsay, Scotland, the bride's mother, Cecilia Bleasdale, took a photograph of a dress at Cheshire Oaks Designer Outlet north of Chester, England.

Cates Holderness, who ran the Tumblr page for BuzzFeed at the site's New York offices, received a message from McNeill asking for help resolving the colour dispute of the dress.

[5] Holderness showed the picture to other members of the BuzzFeed social media team, who immediately began arguing about the dress colours.

On Twitter, users created the hashtags "#whiteandgold", "#blueandblack", and "#dressgate" to discuss their opinions on what the colour of the dress was, and theories surrounding their arguments.

[5] The photo also attracted discussion relating to the triviality of the matter as a whole; The Washington Post described the dispute as "[the] drama that divided a planet".

[2][8][9] Some articles humorously suggested that the dress could prompt an existential crisis over the nature of sight and reality, or that the debate could harm interpersonal relationships.

[11] On the evening BuzzFeed posted the article, the Wellesley College neuroscientist Bevil Conway gave some comments about the phenomenon to the Wired reporter Adam Rogers.

When Conway woke up the next morning, his inbox had so many emails he initially thought it had been hacked, until he saw that most were interview requests from major media organisations.

[5] Jaden Smith, Frankie Muniz, Demi Lovato, Mindy Kaling, and Justin Bieber saw the dress as blue and black, while Anna Kendrick, B. J. Novak, Katy Perry, Julianne Moore, and Sarah Hyland saw it as white and gold.

[19] In the UK, where the phenomenon had begun, Ian Johnson, creative manager for Roman Originals, learned of the controversy from his Facebook news feed that morning.

Everyone from QVC to Warner Bros. to local public libraries to Red Cross affiliates were all posting links to it on their social accounts.

[22] The dress was cited by CNN commentator Mel Robbins as a viral phenomenon having the requisite qualities of positivity bias incorporating "awe, laughter and amusement" and was compared to and contrasted with a story about escaped llamas in an Arizona retirement community earlier that day, as well as to tributes paid to actor Leonard Nimoy after his death the following day.

The day after McNeill's post, Roman Originals' website experienced a major surge in traffic and sold out of the dress within 30 minutes.

[28] On 28 February, Roman Originals announced that they would make a single white and gold dress for a Comic Relief charity auction.

[32] The neuroscientists Bevil Conway and Jay Neitz believe they are a result of how the human brain perceives colour and chromatic adaptation.

[33]Similar theories have been expounded by the University of Liverpool's Paul Knox, who stated that what the brain interprets as colour may be affected by the device the photograph is viewed on, or the viewer's own expectations.

[48][49] A study carried out by Schlaffke et al. reported that individuals who saw the dress as white and gold showed increased activity in the frontal and parietal regions of the brain.

[6] In South Africa, the Salvation Army used the dress in a 2015 campaign to raise awareness of domestic violence, with the slogan: "Why is it so hard to see black and blue?