Rainbow rose bushes are not created by nature. A rainbow rose is made by strategically inserting the stem into dyes made from naturally occurring plant extracts. Rainbow roses are only available as a cut flower and not in bush or seed form.
To grow rose petals that are various colors, the stem is cut vertically into four even parts. Each quarter is then dipped into a different color dye. The dye travels up the xylem to the petals with each petal being a different color according to its placement. The technique for making rainbow roses was introduced by Peter van de Werken of Holland.