Celebrity baby names are always source of much news and debate, usually because they generate debate over how the names actually came to be. For example, ever since singers Beyonce and Jay Z named their first daughter Ivy Blue, much has been speculated on how the name came to be and more attention was focused when the couple copyrighted her name.

Some suggested blue was Beyonce's favourite colour, as also Jay-Z. The rapper sang "My favourite hue is Jay-Z blue" in the song Go Crazy. In addition, he also released an album called Blueprint, leading to more speculation.

Now, however, it seems all has been revealed

Beyonce posted a passage - from Rebecca Solnit's 2005 novel A Field Guide to Getting Lost - on her official Tumblr account. The following is the excerpt posted by Beyonce on her Tumblr page:

The passage starts and ends praising the colour blue. The description of the passage is given on her Web site, along with a picture of the singer sitting with blue nail polish. Apparently, Beyonce is a huge fan of Solnit.

The name Ivy is believed to stand for the Roman numeral IV. According to the Daily Mail, the number four is significant to the couple. The pair were married on 4 April, 2008 and it is the title of Beyoncé's latest album. In addition, the singer's birthday is 4 September and her hip hop star beau's is 4 December.

After the birth of their daughter on 7 January, Jay Z and Beyonce have often been seen beaming with pride. Both parents have slowed down from their earlier busy schedules to spend more time with their daughter.

"After my daughter was born I thought I would be more inspired with all the new feelings and everything that I'd have to write about, but it really happened the other way. I just really wanna hang out with her. I just wanna enjoy those moments for a bit and I'm sure that feeling of music will come back to me," Jay Z earlier said.