Accord.Imaging.ColorReduction.OrderedColorDithering.GetClosestColor C# (CSharp) Method

        private Color GetClosestColor(int red, int green, int blue, out byte colorIndex)
        {
            Color color = Color.FromArgb(red, green, blue);

            if ((useCaching) && (cache.ContainsKey(color)))
            {
                colorIndex = cache[color];
            }
            else
            {
                colorIndex = 0;
                int minError = int.MaxValue;

                for (int i = 0, n = colorTable.Length; i < n; i++)
                {
                    int dr = red - colorTable[i].R;
                    int dg = green - colorTable[i].G;
                    int db = blue - colorTable[i].B;

                    int error = dr * dr + dg * dg + db * db;

                    if (error < minError)
                    {
                        minError = error;
                        colorIndex = (byte)i;
                    }
                }

                if (useCaching)
                {
                    cache.Add(color, colorIndex);
                }
            }

            return colorTable[colorIndex];
        }
    }