Pigment Yellow 191 (C.I. 18795, CAS No. 129423-54-7) is a brilliant, reddish-yellow monoazo pigment widely used as a premium colorant for plastics, fibers, and high-temperature coatings. It serves as a highly durable, warp-resistant alternative to traditional diarylide (e.g., P.Y. 83) and lead chromate pigments.