The pink solid formed when ammonia (not millennium) is added to copper sulfate solution is copper hydroxide (Cu(OH)₂).

Here's why:

* Copper sulfate (CuSO₄) is a blue solution.

* Ammonia (NH₃) is a base.

* When ammonia is added to copper sulfate, a chemical reaction occurs, resulting in the formation of copper hydroxide and ammonium sulfate:

```

CuSO₄ (aq) + 2NH₃(aq) + 2H₂O(l) → Cu(OH)₂ (s) + (NH₄)₂SO₄ (aq)

```

* Copper hydroxide (Cu(OH)₂) is a light blue, gelatinous precipitate that appears pink in the presence of excess ammonia.

Important Note: If you continue adding ammonia to the solution, the pink copper hydroxide will dissolve and form a deep blue solution containing the tetraamminecopper(II) complex ion, [Cu(NH₃)₄]²⁺.