顏色轉換：HSB顏色 與 RGB顏色

        /// <summary>
        /// HSB轉RGB
        /// </summary>
        /// <param name="hue">色調，°，0~360</param>
        /// <param name="saturation">飽和度，%, 0~100</param>
        /// <param name="brightness">亮度，%, 0~100</param>
        /// <returns>返回：Color</returns>
        public Color HSB2RGB(float hue, int saturation, int brightness)
        {
            double r = 0;
            double g = 0;
            double b = 0;

            hue = hue % 360;
            float sat = saturation / 100.0f;
            float bri = brightness / 100.0f;

            if (sat == 0)
            {
                r = g = b = bri;
            }
            else
            {
                // the color wheel consists of 6 sectors. Figure out which sector you're in.
                double sectorPos = hue / 60.0;
                int sectorNumber = (int)(Math.Floor(sectorPos));
                // get the fractional part of the sector
                double fractionalSector = sectorPos - sectorNumber;

                // calculate values for the three axes of the color. 
                double p = bri * (1.0 - sat);
                double q = bri * (1.0 - (sat * fractionalSector));
                double t = bri * (1.0 - (sat * (1 - fractionalSector)));

                // assign the fractional colors to r, g, and b based on the sector the angle is in.
                switch (sectorNumber)
                {
                    case 0:
                        r = bri;
                        g = t;
                        b = p;
                        break;
                    case 1:
                        r = q;
                        g = bri;
                        b = p;
                        break;
                    case 2:
                        r = p;
                        g = bri;
                        b = t;
                        break;
                    case 3:
                        r = p;
                        g = q;
                        b = bri;
                        break;
                    case 4:
                        r = t;
                        g = p;
                        b = bri;
                        break;
                    case 5:
                        r = bri;
                        g = p;
                        b = q;
                        break;
                }
            }
            int red = Convert.ToInt32(r * 255);
            int green = Convert.ToInt32(g * 255);
            int blue = Convert.ToInt32(b * 255); ;

            return Color.FromArgb(Convert.ToByte(255), red, green, blue);
        }

        /// <summary>
        /// RGB轉HSB
        /// </summary>
        /// <param name="red"></param>
        /// <param name="green"></param>
        /// <param name="blue"></param>
        /// <param name="hue"></param>
        /// <param name="sat"></param>
        /// <param name="bri"></param>
        public void RGB2HSB(int red, int green, int blue, out double hue, out double sat, out double bri)
        {
            double r = ((double)red / 255.0);
            double g = ((double)green / 255.0);
            double b = ((double)blue / 255.0);

            double max = Math.Max(r, Math.Max(g, b));
            double min = Math.Min(r, Math.Min(g, b));

            hue = 0.0;
            if (max == r && g >= b)
            {
                if (max - min == 0) hue = 0.0;
                else hue = 60 * (g - b) / (max - min);
            }
            else if (max == r && g < b)
            {
                hue = 60 * (g - b) / (max - min) + 360;
            }
            else if (max == g)
            {
                hue = 60 * (b - r) / (max - min) + 120;
            }
            else if (max == b)
            {
                hue = 60 * (r - g) / (max - min) + 240;
            }

            sat = (max == 0) ? 0.0 : (1.0 - ((double)min / (double)max));
            bri = max;
        }