Explain about natural pigments

There has been an extensive search of the microbial, plant and animal kingdoms for pigments that possess both high tinctorial power/strength (a measure of the potential colouring power of a colourant) and stability, but so far, no exceptional candidates have emerged. The instability of the common natural colourants in food has been studied to seek the means of stabilization and the environment in which the pigments exist in nature, has been investigated for the same reason.