C# Color scale Wavelength to RGB

private Color getColorFromWaveLength(int Wavelength)
        {
            double Gamma = 1.00;
            int IntensityMax = 255;
            double Blue;
            double Green;
            double Red;
            double Factor;

            if (Wavelength >= 350 && Wavelength <= 439)
            {
                Red = -(Wavelength - 440d) / (440d - 350d);
                Green = 0.0;
                Blue = 1.0;
            }
            else if (Wavelength >= 440 && Wavelength <= 489)
            {
                Red = 0.0;
                Green = (Wavelength - 440d) / (490d - 440d);
                Blue = 1.0;
            }
            else if (Wavelength >= 490 && Wavelength <= 509)
            {
                Red = 0.0;
                Green = 1.0;
                Blue = -(Wavelength - 510d) / (510d - 490d);

            }
            else if (Wavelength >= 510 && Wavelength <= 579)
            {
                Red = (Wavelength - 510d) / (580d - 510d);
                Green = 1.0;
                Blue = 0.0;
            }
            else if (Wavelength >= 580 && Wavelength <= 644)
            {
                Red = 1.0;
                Green = -(Wavelength - 645d) / (645d - 580d);
                Blue = 0.0;
            }
            else if (Wavelength >= 645 && Wavelength <= 780)
            {
                Red = 1.0;
                Green = 0.0;
                Blue = 0.0;
            }
            else
            {
                Red = 0.0;
                Green = 0.0;
                Blue = 0.0;
            }
            if (Wavelength >= 350 && Wavelength <= 419)
            {
                Factor = 0.3 + 0.7 * (Wavelength - 350d) / (420d - 350d);
            }
            else if (Wavelength >= 420 && Wavelength <= 700)
            {
                Factor = 1.0;
            }
            else if (Wavelength >= 701 && Wavelength <= 780)
            {
                Factor = 0.3 + 0.7 * (780d - Wavelength) / (780d - 700d);
            }
            else
            {
                Factor = 0.0;
            }

            int R = this.factorAdjust(Red, Factor, IntensityMax, Gamma);
            int G = this.factorAdjust(Green, Factor, IntensityMax, Gamma);
            int B = this.factorAdjust(Blue, Factor, IntensityMax, Gamma);

            return Color.FromArgb(R, G, B);
        }