// texture pigment attribute
// RGB values can range from 0.0 (dark) to 1.0 (saturated)
  color red 0.5 green 0.5 blue 0.5 // filter 0.8
// (---alternative form---)
  //color rgb <0.5, 0.5, 0.5>
  //color rgbf <0.5, 0.5, 0.5, 0.8>
