Just as fictional detective Nero Wolfe pursued the elusive black orchid, growers the world over have spent centuries searching out exotic rose colors. Although most colors have now been created, two continue to frustrate and challenge rose growers. Black and blue roses are still not available, and green roses are few and unusual.
In the mid-19th century, a prize of 500,000 francs was offered to the developer of a blue rose. The prize has never been claimed. To date, the closest attempt, a lilac colored rose, was only created through gene replacement treatment using an artificially created gene. The Midnight Blue rose, one of the few naturally created "blue" roses, is actually a deep purple.
While black roses are popular in weddings and other events, these are not naturally occurring roses. The black roses that are truly black are rose that have been dyed black by florists. The closest roses to black are either extremely deep shades of red, or variations of dark red roses with deep purple accents. The Black Baccara rose is one such, a very dark red rose with purple, almost black, markings on the edge of the petals. The Black Jade is another so-called black rose with deep red petals and some splotches of dark purple petals.
Green roses are available, but often they, too, are dyed to a vibrant green. A naturally occurring green rose is usually a rose that has been grown deliberately in shade to produce green blooms. Even so, only a few verities of roses will do this. These include the miniature roses Green Ice and Green Diamond, the floribunda Greensleeves, and the Green Rose. This rose is unusual in that it has no petals. The bloom is made up entirely of green sepals.