A blue rose is a flower of the genus Rosa (family Rosaceae) that presents blue-to-violet pigmentation instead of the more common red, white, or yellow. Blue roses are often portrayed in literature and art as a symbol of love and prosperity to those who seek it, but do not exist in nature as a result of genetic limitations. White roses have been dyed blue. In 2004, researchers used genetic modification to create roses that contain the blue pigment delphinidin.
In some cultures, blue roses are traditionally associated with royal blood, and thus the blue rose can also denote regal majesty and splendor. In Chinese folklore, the blue rose signifies hope against unattainable love.
Due to the absence in nature of blue roses they have come to symbolise mystery and longing to attain the impossible, with some cultures going so far as to say that the holder of a blue rose will have his wishes granted.