clear area or between adjacent areas having different color filters may for example be fabricated as a pattern of disjoint regions of clear material interspersed with conjoined regions of color filter material the density of clear regions may increase until at some point the regions of clear material become conjoined and the regions of color filter material become disjoint the density of color filter regions may then decrease until the gradual transition from color filter to clear is complete it will be understood that other techniques known in the art may be used to produce gradual transitions from colored to clear or from one color to another color diffusion pattern string 310 is illustrated as having panels k p the panels k and p may comprise leader material used to attach the diffusion pattern string 310 to the rollers of the scrolling mechanism 110 the panels l o may comprise for example holographic lens material such as the lsd u00ae light shaping diffuser film manufactured by physical optics corporation of torrance calif the panels l o may comprise material selected to provide a graduated sequence of increasing omni directional diffusion producing round beams of increasing degrees of divergence in another embodiment of the invention one or more of panels l o may comprise material providing differing amounts of divergence in the horizontal and vertical directions producing rectangular beams of differing degrees of divergence thus the scrolling mechanism 110 may be operated to position any of the panels l o across the mouth of the reflector 104 the panels l o as described may act to diffuse the light beam to.