Asker's rating. Report Abuse. when iron filings are added to copper sulphate solution the blue colour of copper sulphate fades away due to the formation of new product and the colour of iron filing becomes brown.nswers. Best Answer: The iron filings become brownish in color and the blue color of color of copper sulphate solution fades. This is because iron, being more reactive than copper displaces copper from copper sulphate solution. Fe(s) + CuSO4(aq) --- FeSO4(aq) + Cu(s).