Cyanin is a vegetable blue, or rose color, which reddens by the action of acids. Blue flowers are found to possess a neutral juice, while the juices of red flowers have an acid reaction ...

Colors evolved for survival, with animals using them for warnings and mating, and plants attracting pollinators.

Hydrangeas are one of the only types of flowers that can change color. The change in hue happens in response to the availability of aluminum. These gorgeous landscaping plants are like pH alarms ...