 Four dihalides of cobalt ( II ) are known : cobalt ( II ) fluoride ( <unk> , pink ) , cobalt ( II ) chloride ( <unk> , blue ) , cobalt ( II ) bromide ( <unk> , green ) , cobalt ( II ) iodide ( <unk> , blue @-@ black ) . These halides exist in anhydrous and hydrated forms . Whereas the anhydrous dichloride is blue , the hydrate is red . 
