How can you make a pipe change colors? Have you seen a pipe that after it was smoked you see some beautiful blues, greens or pinks come out of seemingly nowhere? That is color changing. But how can this be done? Well, the trick is that it's actually called fuming. This is the act of taking either silver or gold and heating it to a point that it turns to gas and attaches to the pipe. Then the pipe is heated and shaped until the gold or silver fume becomes one with the glass. Then when the pipe is used, the resin creates a backdrop for the fume to stand out. This can be a fun surprise when it's not expected, but can also be a reason to get a piece and to point out to the person interested in a new piece.