Why Pistachios are red– Before american farmers got in on growing pistachios, most pistachios found in the United States were imported from places like Iran and Turkey. The harvesting methods used by international farmers often left blemishes on the shell of the pistachios in turn making them less desired. Consequently the companies that importing pistachios into the US would often dye them red or green in order to cover up the blemishes and make them more appealing to american consumers.
Thanks to advances in harvesting technology as well as the growth in american pistachio farming, there is a great supply of pistachios to be found right here in the US, and specifically Arizona. And because of the methods used to harvest they have no need to add harmful dyes to the naturally beautiful nuts.