k3d/share/shaders/k3d_lensflare.sl:22: *   rainbowintensity - intensity of rainbow effect (0=none)
k3d/share/shaders/k3d_lensflare.sl:94:		      float rainbowintensity = 0.03;
k3d/share/shaders/k3d_lensflare.sl:167:    if(rainbowintensity > 0)
k3d/share/shaders/k3d_lensflare.sl:170:	  brightness * (rainbowintensity / intensity) *
