It is the question that has divided the internet: is this dress white and gold, or blue and black?
The two-toned frock has sparked a fierce online debate, with users taking to social media to argue over what colours they see.
The picture of the dress was first posted on Tumblr by Caitlin McNeill, a 21-year-old aspiring singer from Scotland, after noticing her friends saw different colours in the photograph.
The image has become an online sensation, with posts arguing over the dress's original colours - and science behind the debate - being viewed and shared millions of times.
Even celebrities weighed in on the fashion debate, with Kim Kardashian asking her 29.4million Twitter followers to help settle a disagreement between herself and husband Kanye West.
And #TheDress started trending worldwide on Twitter as the debate when global. At 3.15pm this afternoon, there had been more than 1 million tweets mentioning the hashtag.
The photograph that started the internet storm was taken by Cecilia Bleasdale while she was deciding on what to wear to her daughter's upcoming wedding.
Ms Bleasdale sent the picture of the frock to her daughter, Grace , to ask the bride-to-be what she thought. Grace, in turn, shared it with her then-fiance, Kier Johnston.
The couple disagreed over the colours of the dress, which can be purchased here, and here, Grace sought more opinions online.
The bride-to-be then posted the picture on Facebook, and her friends continued to debate the colour of the dress.
The debate was forgotten until Caitlin McNeill, a close friend of the newlyweds, posted the picture on Tumblr days after the wedding, which took place on Saturday on the Scottish island of Colonsay.
Ms McNeill, whose folk band played at the ceremony, shared the photograph on a fan page dedicated to talent manager Sarah Weichel.
Weichel, who represents YouTube stars, told Business Insider last night that her phone began blowing up on Thursday after McNeill's post started going viral.
'The crazy thing is, I actually have nothing to do with the post,' she said. 'But I have been getting a ton of phone calls and emails tonight.'
The page gave the dress the exposure that sent it into the online stratosphere.
It was quickly picked up by bloggers, news outlets and Twitter users, who have spent the last 24 hours commenting on the dress - and the debate it has spared.
Speaking to Business Insider, Ms McNeill, said she couldn't believe the way the dress has exploded online.
She said: 'I thought my followers on Tumblr would maybe have a good reaction, but I never would have considered that Taylor Swift and Mindy Kaling would be tweeting about it.'
Meanwhile, as the newlyweds enjoy their honeymoon in Jamaica, their friends and families have been shocked by the coverage over the dress.
Mr Johnston's mother, Shirley Johnston, 62, said the reaction had been 'really weird' while 26-year-old Lindsay Maden, from Blackpool, who was a bridesmaid at the wedding, described it as 'mental'.
The bride's sister, Angie McPhee, 27, said that she thought the newly-married couple were unaware of the social media storm.
She said: 'I think Grace is going to wake up in Jamaica and think oh my god, what is going on.'
Commenting on how the dress looked on her mother, Miss McPhee said: 'Fabulous. She looked absolutely fabulous on the day.'
Millions have since joined the raging debate - dubbed 'dressgate' - with a number of high-profile celebrities among those who have weighed in on the issue.
Actress Mindy Kaling also joined the discussion, writing on Twitter: 'IT'S A BLUE AND BLACK DRESS! ARE YOU F***ING KIDDING ME'.
Her friend and fellow actor BJ Novak replied writing, 'white and gold.'
