This a very visual rope trick that will fool even most magicians, yet is very simple to perform.
You show a plain red color rope. You tie a knot on this rope. As you pass your hand over the RED knot on the red rope, the knot changes color and you now have a BLUE knot. The BLUE knot then changes color to a YELLOW knot. When the YELLOW knot is opened, it is found to have blended with red rope and you now have a yellow rope on the red rope.
The rope is about 5' in length and is made of very high quality, bright colored, soft crotchet material.