code: public static float[] toArithmeticRGB(float hue, float saturation,
  			float lightness) {
  
  		validateHue(hue);
  		validateSaturation(saturation);
  		validateLightness(lightness);
  
  		hue /= 60.0f;
  		float t2;
  		if (lightness <= 0.5f) {
  			t2 = lightness * (saturation + 1);
  		} else {
  			t2 = lightness + saturation - (lightness * saturation);
  		}
  		float t1 = lightness * 2.0f - t2;
  
  		float red = hslConvert(t1, t2, hue + 2);
  		float green = hslConvert(t1, t2, hue);
  		float blue = hslConvert(t1, t2, hue - 2);
  
  		return new float[] { red, green, blue };
  	}
docs: Convert HSL (hue, saturation, and lightness) values to RGB arithmetic
  values
  
  @param hue
  hue value inclusively between 0.0 and 360.0
  @param saturation
  saturation inclusively between 0.0 and 1.0
  @param lightness
  lightness inclusively between 0.0 and 1.0
  @return arithmetic RGB array where: 0 = red, 1 = green, 2 = blue