'I thought #TheDress was gold & white' says musician behind Twitter megatrend

It's the latest story to break the internet - and an optical illusion.

Is this dress blue and black or white and gold?

Scottish singer Caitlin McNeill, 21, started the whole debate after posting a picture of #TheDress on her Tumblr blog.

"Two of my very good friends were getting married and they asked me to put together a band to come and play at their wedding in Western Scotland," she's told Newsbeat.

"This was a wedding on the tiny island that we come from on the west coast of Scotland called Colonsay and about 100 people were there.

"A week beforehand the bride had been sent, by her mother, a picture of the dress she was going to wear and when the bride showed her fiance, they disagreed about what colour it was.

"She was like, 'It's white and gold' and he said, 'It's blue and black'.

"So they posted it on Facebook to try and see what their friends were saying but that caused carnage on Facebook.

"We forgot about it until we saw it at the wedding, which the mother of the bride was wearing, and it was obviously blue and black.

"When I got off the island last night, I was sitting in my hotel room and I thought, 'I'll maybe put the picture to my Tumblr followers.' Sometimes Tumblrs debunk these things and I thought they might have some ideas.

Listen to the full interview on Newsbeat's SoundCloud

"I posted it onto Tumblr, it somehow got onto Twitter and then it just went crazy after that."

That craziness has translated into #TheDress trending around the world.

Also trending are #blueandblack and #goldandwhite as well as various other versions of those colours.

Caitlin says she never expected this reaction after posting the picture on Tumblr.

"It's just incredible. I can't comprehend it.

"People have been messaging me saying that all their favourite celebrities are tweeting about it. I can't even believe it's real. I feel like I'm dreaming."

Even though Caitlin originally thought the dress was gold and white herself, she says after seeing it in person it's definitely blue and black.

"When my friend originally posted this picture on Facebook I thought they were just playing an elaborate prank on me. It took me a very long time to stop thinking that and to realise there was something scientifically amiss here.

"When I saw the dress in blue and black I was like, 'There's not much more I can say about that.'

"Men seem to see it more commonly in blue and black and women see it more commonly in white and gold, in terms of the people I've spoken to.

"But both my brother and my dad saw white and gold."

Roman Originals says it's going to try to get a gold and white version of #TheDress made

There had been suggestions online and on social media that #TheDress was all a publicity stunt designed to promote the company that sells it.

But Caitlin says that's not the case.

"I hadn't even thought about the dress company," she says.

"I did post a link to the company online, just because people were wondering where it had come from.

"I can't express how we've been scratching our heads and stressing and arguing for the last two weeks about this dress and I just wanted to know some answers.

"I didn't know the company until it started blowing up and one of the bridesmaids from the wedding gave me the link to the dress, that's the first I'd heard of it.

"It's going to happen. It's not too bad. If that's the worst people are saying, then that's OK."

And now she's spoken to almost every media outlet in the US and the UK, she says she just wants a bit of sleep.

"Right now I'm going to get some breakfast because I've been on the phone to America all night.

"Maybe a I'll get a wee breakfast and a cup of tea. That would be quite great.

"I've had calls from the New York Times, the Washington Post, Time Magazine, NBC, CBS, ABC - everyone wants a piece of the dress."

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