Often restaurants will use yellow and red food colors to get the color to give the biryani that extra color. And yet, when making biryani for the family I usually only use saffron or omit any colors entirely. In fact, it does not contribute to the taste - just visual appeal. Below you can see two biryani pots - one made with food color and the other made with only the saffron. The edible food colors are brighter in color.