Abstract: Light processing apparatus creates a number of visual effects which simulate movement with light from a light source. A multiplicity of flexible fibre optic light guides having optically finished input and output ends are grouped into groups, with each group being assigned to create a particular effect. The input ends of each group of light guides are placed in adjacent receptor zones of pre-selected geometry, and the output ends of each group of light guides are located on an effects surface in a pre-selected pattern. Light from the light source is filtered by a color changer having a plurality of discrete moveable colored filter zones shaped to correlate with the receptor zones, and is then received by the input ends of the light guides and distributed to the output ends of the light guides. The color changer may be a rotatable color wheel filter, an endless band filter or a cylindrical filter.