Where is a black magic yellow magic and a blue magic

Black magic and green magic and yellow magic, etc:- are just tricks. To work it out you need 2 persons. Both of them must know the trick. The spectator tells in '1''s ears any object that is near you (example computer). '1' asks '2' if it is a wardrobe. (blue wardrobe) 2 will say no. 1 will continue on saying until he says a black colored object. 2 will say no again. Then 1 must say the object that the spectator has said in his ear. Then 2 will say yes because the object before was a black color. 'BLACK MAGIC'.
THE SAME IS BLUE MAGIC: If the magic is blue magic the before object color must be blue, green magic the object be green.