They are the stuff of legend - signifying mystery and traditionally believed to be able to grant the owner youth.
For years breeders have crossed different colours of roses in an effort to create the impossible. But rose petals lack the enzyme needed to create a blue pigment and the breeders always failed.
Now for the first time, thanks to genetic engineering, blue roses finally exist.
The stuff of legend: Blue roses have gone on display in Japan and will be on sale next year
The very first truly blue roses have gone on display in Japan and will be on sale to the public next year.
After 13 years of research the Japanese Suntory company have finally perfected the mythical flower.
Working with the Australian company Florigene the researchers took the delphinidin gene, which creates the blue colour, from a petunia. They then inserted it into a mauve rose called the Cardinal de Richelieu.
The resultant flower was a dark burgundy colour due to an excess of the blue pigment cyanidin.
After using RNAi technology to reduce this the final blue rose was today unveiled at the annual Flower Expo held at Makuhari Messe in Chiba, Japan.
Genetically engineered: The flowers have a gene from a petunia inserted in them