Nickel nitroprusside, Ni[Fe(CN)₅NO]

Nickel nitroprusside, Ni[Fe(CN)₅NO], obtained in a similar manner to the preceding salt, is dark green when anhydrous, but upon exposure to moist air becomes ashen grey. It is insoluble in acids, but readily dissolves in ammonia to a brownish yellow liquid. Potassium hydroxide turns it lemon-yellow.