// create a rainbow arc
rainbow {                      
  angle 30         // degrees
  width 6          // degrees
  distance 1000
  direction <0,-0.5,1>    
  jitter 0.01
  arc_angle 180    // degrees
  falloff_angle 60 // degrees
  // up <UP>
  color_map {
    [0.000 color rgbf <1.0, 0.5, 1.0, 1.0> ]
    [0.100 color rgbf <1.0, 0.5, 1.0, 0.8> ]
    [0.214 color rgbf <0.5, 0.5, 1.0, 0.8> ]
    [0.328 color rgbf <0.2, 0.2, 1.0, 0.8> ]
    [0.442 color rgbf <0.2, 1.0, 1.0, 0.8> ]
    [0.556 color rgbf <0.2, 1.0, 0.2, 0.8> ]
    [0.670 color rgbf <1.0, 1.0, 0.2, 0.8> ]
    [0.784 color rgbf <1.0, 0.5, 0.2, 0.8> ]
    [0.900 color rgbf <1.0, 0.2, 0.2, 0.8> ]
  }
}