Question

What initially forms as pale blue and pale green precipitates when NH3(aq) is added to [Cu(H2O)6]^2+ and [Ni(H2O)6]^2+ solutions, respectively?

Answer 1

Cu^2+ + 4NH3 ==> Cu(NH3)4^2+ blue. May be pale blue in very dilute solutions but more often is a deep blue color.
Ni^2+ behaves similarly but not the same color.