Saffron

Saffron requires over two hundred thousand stigma from crocus sativus flowers to make a pound of saffron. That’s why saffron is the world’s most expensive spice. Fortunately, a little of the good stuff goes a long way – it only takes a few threads to add saffron’s distinct yellow colour and earthy aroma to a family meal. Saffron threads should be red with orange tips. Threads lacking orange tips may dyed, so avoid them. The quality of powdered saffron is measured by its Minimum Coloring Strength. The higher the Minimum Coloring Strength, the less saffron you need to use.
 

Substitutes:  turmeric ( for color, not flavor ; use 4 times as much) safflower (use 8 times as much; less expensive and imparts similar color, but its taste is decidedly inferior), marigold blossoms (for color, not flavor; use twice as much) or read and yellow food coloring