Which of the following statements regarding copper salts is not true?

Copper(II) oxide is black powder.

(A)Copper (I) dispropotionates to copper and copper (II) ion in aqueous solution. Cu2​O+H2​SO4​→CuSO4​+H2​O+Cu. Hence, the statement A is true.
(B)Copper (I) can be stabilized by the formation of insoluble complex compounds such as CuCl2−​andCu(CN)2−​
CuCl+Cl−→CuCl2−​
2Cu+2H++4CN−→2Cu(CN)2−​+H2​. Hence, statement B is true
 Hence, the statement B is true.
(C)  Copper (I) oxide is red power whereas Copper (II) oxide is black solid. Hence, the statement C is not true.
(D) The water of crystallization of copper sulphate is five (CuSO4​.5H2​O). Hence, the statement D is true.