Koro Sensei turns purple when he's feeling superior after giving a correct answer which is most of the time, since he's a tentacled superbeing who moves at Mach 20 and also happens to be the world's best teacher. From Assassination Classroom, this SFC figure captures the beloved teacher-slash-assassination-target in one of his most recognizable color moods. He taught Class 3-E how to kill him while simultaneously teaching them how to live. That's range.
