Diseased Mushroom

There is a rare chance for Mushrooms to spawn on mushroom islands with a disease. (They spawn on diseased mycelium. Which can be farmed  by throwing a linguring poison potion on mycelium.) This will turn the mushroom an odd blue and dark purple. At first the disease is not bad and only part of the block will change. But a lot like copper blocks, over time the block will slowly change. Diseased Mushrooms would be great for the building aspect of minecraft along with many other ways.