Copper(II) hydroxide
Copper(II) hydroxide is light blue. It is rubbery when wet. When it is mixed with copper(II) carbonate, it is greenish. It reacts with carbon dioxide to make copper(II) carbonate when in air. It turns into copper(II) oxide when wet. When it is dry, though, it only turns into copper(II) oxide when it is heated. It reacts with ammonia to make a very dark blue solution.