When metal strips of [[1]] are placed in colourless $\mathit{AgN}{O}_3$ solution, it turns the solution to blue colour.

Copper metal strips when placed in colourless $\mathit{AgN}{O}_3$ solution, turn the solution blue.
Because copper is more reactive than silver, it displaces the silver from the silver nitrate solution and generates a blue copper nitrate solution. As a result, when $\mathit{Cu}$ metal strips are placed in a colourless $\mathit{AgN}{O}_3$ solution, the solution turns blue. The reactivity of the metals can be checked from the reactivity series.
$\mathit{Cu }+ 2\mathit{AgN}{O}_{3 }\to \mathit{ Cu}(N{O}_{3 }{)}_{2 }+ 2\mathit{Ag}$