This simple setup results in a complex, constantly changing pattern of colours within the kaleidoscope. On the end of this triangular kaleidoscope are three discs, one of which turns slowly. Two of the discs are polarising filters, while the third is made from a special plastic that reacts to the polarising filters to produce a range of colours.  A light shining into the end of the kaleidoscope illuminates the discs, and the motion of the one disc causes the colour of the triangular aperture inside the device to change depending on the orientation of the discs to one another. The reflections in the mirrors inside the kaleidoscope appear to be other colours from the one in the aperture, since the colour of the material results from the angle at which it is viewed and from the orientation of the filters to one another.