Researchers found that the bright colors of peacock feathers are not produced by pigments but rather by tiny, intricate two-dimensional crystal-like structures. Slight alterations in the spacing of these microscopic structures cause different wavelengths of light to be filtered and reflected,creating the feathers many different iridescent hues.
No birds were harmed by collecting these feathers !
Peacocks shed their train every year after mating season, so the feathers can just be gathered and enjoyed.

Quick fact : only the males produce these feathers and only the males are called peacocks the collective term for these birds is peafowl the female is called the peahen, and the babies peachicks, the male peachicks don’t start growing their showy trains until about age three.