Fentanyl is a very powerful synthetic opioid that has caused thousands of overdoses and deaths over the past two decades.

In August 2022, drug enforcement authorities noted that pills containing fentanyl were being manufactured in various colors.

DEA Administrator Anne Milgram said, "Rainbow fentanyl – fentanyl pills and powder that come in a variety of bright colors, shapes and sizes – is a deliberate effort by drug traffickers to drive addiction amongst kids and young adults."