Rainbow rose for this colouring process are "Rosa" La Belle and "Rosa" Avalanche+. However, these cultivars' rainbows are not as bright as "Vendela". Some vendors use the cultivar name to describe their products, "e.g.", Vendela Rainbow Rose, or Rose Avalanche Crystal Green. The Original Rainbow Rose has the seven colours of the rainbow and is the most popular rose in this category. However, there are also the tropical variant with combinations of red/pink and yellow, and the ocean variant with combinations of green and blue. Other colour combinations are also possible, though black and white are impossible to make. Rainbow rose The
Rainbow In Europe, Ibn al-Haytham's "Book of Optics" was translated into Latin and studied by Robert Grosseteste. His work on light was continued by Roger Bacon, who wrote in his "Opus Majus" of 1268 about experiments with light shining through crystals and water droplets showing the colours of the rainbow. In addition, Bacon was the first to calculate the angular size of the rainbow. He stated that the rainbow summit can not appear higher than 42° above the horizon. Theodoric of Freiberg is known to have given an accurate theoretical explanation of both the primary and secondary rainbows in 1307. He