Meet the women behind the dress that caused ripples online

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.

The original photograph of the dress was taken by Cecilia Bleasdale, who bought it for her daughter Grace's upcoming wedding.

She sent the image to the bride-to-be, who shared it with her groom. The couple was the to disagree over the dress's colours.

Disagreement erupted when the bride-to-be posted the picture on Facebook, over the colour of the outfit: some said it was white and gold, while others insisted it was blue and black.

The debate reappeared online when Caitlin McNeill, a close friend of Grace and her new husband, Keir Johnston, posted the picture on Tumblr days after the wedding.

Ms McNeill, whose band played at the Scottish ceremony, shared the photograph on a fan page dedicated to talent manager Sarah Weichel, who represents YouTube stars.

That page gave it the exposure that sent the dress into the online stratosphere.

"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,' 21-year-old Caitin McNeil said referring to the celebrities that have joined in the conversation.

The dress has also being confirmed as blue with black lace detailing.

It is made by British clothing company Roman Originals, which offers 'affordable women's clothing and designer ladies fashion.'

Ian Johnson, of Roman Originals said: "We were absolutely ecstatic about the reception of our fabulous blue and black dress. We see blue and black but some people in the office see white and gold too, so much so we’re thinking of doing a white and gold version! We sold out within the first 30 minutes of sale and have since restocked all colours and sizes," she said.

The simple scientific answer behind the debate is that it is an optical illusion.

Objects reflect light at certain wavelengths, or colours, and the human brain determines the colour of an object by taking in its reflected light.

But this perception can be thrown off balance by the colour of nearby objects.

According to Wired.com, a digital analysis of the dress photo shows that one of the spots of black trim is actually orange in the photo making people who perceive the surrounding area as dark to see the blue in the dress as white and the black colours as gold.

It all just depends on the manner that the brain perceives and processes colour, the website writes.