Micaceous Iron Oxide is a deep warm brown, that is in the same family as Caput Mortuum and is in the same family as our Mars Terracotta, Mars Venetian Red and Transparent Red Earth. Our Micaceous Iron Oxide also known as MIO has a warm, reddish undertone and a moderate tinting strength. MIO cools off quickly with the addition of white, and is our most neutral brown. MIO is also referred to as Brown Pink, Sepia, and Transparent Brown Oxide.