Term: Blue, Description: A primary colour between purple and green, Question: Is the most expensive color in the world Blue?, Answer:Yes
Fact1: Blue is a primary color. Fact2: Blue is between violet and green on the visible light spectrum. Fact3: Lapis Lazuli is used to make ultramarine.  Fact4: Ultramarine is a pigment of Blue Fact5: Processing Lapis Lazuli into Ultramarine is the most expensive of color processes. 