code: func SolidColor(inColor color.Color) ColorFunc {
  	return func(n int, x int, y int, maxN int, maxX int, maxY int) color.Color {
  		return inColor
  	}
  }
docs: // SolidColor generates a ColorFunc which simply returns the input color
  // as the color which should be drawn at all coordinates.
  //
  // This is the default behavior of the waveform package.