We have been using saffron to make risotto and paella yellow for centuries. Saffron, though, is very expensive. Now there is a new patented process to make rice in red, yellow, green, and purple, with the caveat that green does not survive cooking. I wonder if an orange risotto, which in addition to saffron would use ang-khak rice mold, would be less fattening, given the statins in Monascus purpureus.
Here is the article from Focus Taiwan.
A government-assisted farmers' research group in eastern Taiwan has developed "colorful" rice — no longer rice in white, but in four different colors — red, yellow, green and purple. The Hualien District Agricultural Research and Extension Station — which is dedicated to helping local farmers improve their earnings from farming, including by coming up with new products — said it has spent seven years developing the technology to add natural colors to rice using vegetables. "The colorful rice can add interest, enrich your visionary sight and increase your appetite, especially for children," the station said. It said that Southeast Asian countries and India have used natural colors to cook rice since ancient times, mostly using turmeric (a plant of the ginger family) and herbs to give rice color. It said that using the natural colors of vegetables to produce colorful rice is both "safe and delicious." The four colors developed by the station — red, yellow, green and purple — are derived from using anka (red yeast, Monascus purpureus), turmeric, chlorophyll (green pigment derived from green vegetables) and anthocyanidin (plant pigment). The station noted that rice colored with anka, turmeric, and anthocyanidin will not change color during the cooking process. The green color, using chlorophyll, however, tends to turn into an olive color after cooking. "The best ingredient is using something that is natural," the station said. It said that it is not only targeting families as the main consumers of colorful rice, but is also eying hostels or leisure farms, which may want to use it for creative dishes. They could also make it a souvenir or gift for visitors, he said. In the earlier days of research into making colorful rice, the technology could only produce a small amount of colorful rice, according to the station. But after further development, it has come up with the technology for mass production, and has obtained a patent. The station later transferred the technology to the private sector, which can now produce two metric tons of colorful rice each day.