"Law enforcement officers have extreme difficulty — extreme difficulty — in distinguishing between the real thing and what is fake ... especially when officers must make a split-second decision in a very dangerous situation," de Leon said.
He added later, "This is about saving lives."
More than 200 such shootings occur each year across the country, he said, citing a 1990 U.S. Department of Justice study.
Several Republicans objected that the bill could endanger police officers because some real guns are now manufactured in different colors to appeal to consumers including children.
Smith & Wesson, for instance, makes several handguns with pink hand grips to appeal to women.