This trick has variously been described as ‘one of the greatest magical effects I have ever witnessed’ and ‘ one of the prettiest effects I have ever seen’. This is what the audience see. Williams has a small box covered in red cloth both inside and out, and a green handkerchief. Lowering the green silk in the box and taking it out again he remarks “I have here a red handkerchief and a green box”. He repeats that remark several times until the audience start to laugh as it is quite obvious that he is wrong, as the box is red and the silk is green. He then lowers the silk into the box once again and upon removing it the colour is seen to be red while the box visibly changes to green, both inside and out.
It is one of the most cunning pieces of apparatus I have ever seen.