Team B.S. turn an abandoned mine's diamonds into a diamond block, then fight through the Nightmarish Nursery and find the Withered Soul needed for the black wool.
Team B.S. dive into a flooded dungeon full of guardians and charged creepers, hunt for air and a way through, and bring the blue wool back to the monument.
Team B.S. put an iron block on the monument, lose Basket to a witch in the lab, brew splash potions, and pull a wool out of a room built over the void.
Team B.S. fetch a skipped emerald, then fight through the Haunted Hedges maze and the catacombs beneath it to find the gray wool, with rabbits underfoot the whole way.