// texture pigment {} attribute
// create a smooth color gradation map
// gradient <> // orients the direction of the color_map
color_map
{
  // [ END_VAL color red R green G blue B filter F]
  //   -or old style-
  // [ START_VAL END_VAL color red R green G blue B filter F color red R green G blue B filter F]
  [  0.1  color red 0.0 green 0.0 blue 0.0]
  [  0.3  color red 0.8 green 0.4 blue 0.2]
  [  0.5  color red 0.0 green 0.0 blue 0.0]
  [  0.7  color red 0.0 green 0.0 blue 0.8 filter 0.5]
  [  1.0  color red 0.8 green 0.8 blue 0.8 filter 1.0]
} // color_map