azo dye-based pigment (a brightly colored transparent or semitransparent dye with a white pigment) is used as the colorant in most modern paints requiring either a highly saturated yellow or simplicity of color mixing. The most common is the monoazo arylide yellow family, first marketed as Hansa Yellow. Dyes Curcuma longa, also known as turmeric, is a plant grown in India and Southeast Asia which serves as a dye for clothing, especially monks' robes; as a spice for curry and other dishes; and as a popular medicine. It is also used as a food coloring for mustard and other products. Saffron, like turmeric, is one of the rare dyes that is also a spice and food colorant. It is made from the dried red stigma of the crocus sativus flower. It must be picked by hand and it takes 150 flowers to obtain a single gram of stigma, so it is extremely expensive. It probably originated in the Mediterranean or Southwest Asia, and its use was detailed in a 7th-century BC Assyrian botanical reference compiled under Ashurbanipal. It was known in India at the time of the Buddha, and after his death his followers decreed that monks should wear robes the color of saffron. Saffron was used to dye the robes of the senior Buddhist monks, while ordinary monks wore robes dyed with Gamboge or Curcuma longa, also known as Turmeric. The color of saffron comes from crocin, a red variety of carotenoid natural pigment. The color of the dyed fabric varies from deep red to orange to yellow, depending upon the type of saffron and the process. Most saffron today comes from Iran, but it is also grown commercially in Spain, Italy and Kashmir in India, and as a boutique crop in New Zealand, the United Kingdom, France, Switzerland and other countries. In the United States, it has been cultivated by the Pennsylvania Dutch community since the early 18th century. Because of the high price of saffron, other similar dyes and spices are often sold under the name saffron; for instance, what is called Indian saffron is often really turmeric. Reseda luteola, also known as dyers weed, yellow weed or weld, has been used as a yellow dye from neolithic times. It grew wild along the roads and walls of Europe, and was introduced into North America, where it grows as a weed. It was used as both as