When choosing infinity roses, people have many different choices to go for, with red, pink, white and yellow among the common rose colours you can choose for a product that will last years.
The idea of the deep blue sea rose, however, is quite a novelty, as is the Over the Rainbow Forever Rose with its mix of pink and blue. After all, one can visit many a rose garden and never see them growing there.
What makes this notable is that it does not apply with so many other flowers. After all, we see bluebells, forget-me-nots, cornflowers and many other blue blooms around. So why, one may ask, has no breeder ever produced a blue rose?
The reason lies in the pigment - delphinidin - that occurs in blue flowers. This relies on low levels of acidity to be blue. However, rose petals have a high level of acidity, which turns such pigment pink, red or purple, as happens in cranberries.
Moreover, the sac containing the pigment is very efficient at keeping alkalines out. The only way to do so would be to mash up the rose petals and add alkaline to the juice to create blue - which is not what anyone is aiming for.
To prevent this, therefore, the only solutions would be to find a different blue-producing pigment or create a rose with an alkaline metabolism.
The difficulty with blue pigments is there are extremely few of them. While plants use PH-dependent pigments and often come out blue, almost no blue animals owe their colour to pigment, with most getting it by the structures of skin, scales or feathers to scatter all other wavelengths of light, the same effect that makes the sky blue.
Among very few exceptions to this is the Olivewing Butterfly, which has blue pigment in its wing markings. But nobody has (yet, at least) ever made a blue rose by transplanting butterfly pigment.
Blue infinity roses are actually produced with blue dye in white roses, which may seem like cheating, but it does provide a wonderful, rich colour that lasts. And until a blue rose can be engineered another way, you can be sure it will stand out.