Dyed Roses also known as Tinted Roses. Black Roses, Rainbow Roses and Blue Roses are created by florists. Black Roses, Rainbow Roses and Blue Roses can not produced in nature, they were dyed or tinted black from other roses with dye or food coloring to give a black, rainbow or blue color appearance.
Black Roses, don’t occur naturally but can be dyed from deep red roses, however there are hybrid very dark red roses that are passed as black roses
Rainbow Roses are the multi-colored roses and also don’t grow naturally. You can Make you own Rainbow Rose using a white rose and food coloring.
Blue Roses - another color that is not naturally occurring is Blue Roses
Dyed Roses also known as Tinted Roses are unnaturally coloured achieved by dying regular roses, they don't last as long in a vase as regular roses, as the dye affects the plants' ability to photosynthesise and survive. You cannot grow black roses or blue roses or rainbow roses naturally from bulbs are seeds, despite seller claims on eBay. They have many uses, especially in the corporate flower market where matching corporate colours, logos & product packaging colours is required.