Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

(N/A) When an iron nail is placed in a copper sulphate solution,iron being more reactive than copper,displaces copper from the copper sulphate solution. This reaction forms iron sulphate,which is green in colour.
$Fe_{(s)} + CuSO_{4(aq)} \rightarrow FeSO_{4(aq)} + Cu_{(s)}$
In this reaction,the blue colour of the copper sulphate solution fades as it is converted into light green iron sulphate solution,and a reddish-brown deposit of copper is formed on the iron nail.