Current Border Script

public static Bitmap AddColorsBorder (Bitmap originalMap, List<Color> colorsToBorder, int borderRadius, Color borderColor, BorderPosition borderPos) //Border Position is an Enum
    {
        DirectBitmap result = DirectBitmap.fromBitmap(originalMap);

        int x, y;


        for (x = 0; x < result.Width; x++)
        {
            for (y = 0; y < result.Height; y++)
            {
                if (colorsToBorder.Contains(result.GetPixel(x, y)))
                {
                    List<(int, int)> currentPixels = new List<(int, int)>();
                    List<(int, int)> nextPixels = new List<(int, int)>();
                    List<(int, int)> allPixelsToWrite = new List<(int, int)>();

                    currentPixels.Add((x,y));

                    for (int curRadius = 0; curRadius <= borderRadius; curRadius++)
                    {
                        if (currentPixels.Count == 0) break;
                        foreach ((int, int) pixel in currentPixels)
                        {
                            if (borderPos == BorderPosition.Center)
                            {
                                if (pixel.Item1 + 1 < result.Height) {nextPixels.Add((pixel.Item1 + 1, pixel.Item2));
                                allPixelsToWrite.Add((pixel.Item1 + 1, pixel.Item2));}
                                if (pixel.Item1 - 1 > 0) {nextPixels.Add((pixel.Item1 - 1, pixel.Item2));
                                allPixelsToWrite.Add((pixel.Item1 - 1, pixel.Item2));}
                                if (pixel.Item2 + 1 < result.Height) {nextPixels.Add((pixel.Item1, pixel.Item2 + 1));
                                allPixelsToWrite.Add((pixel.Item1, pixel.Item2 + 1));}
                                if (pixel.Item2 - 1 > 0) {nextPixels.Add((pixel.Item1, pixel.Item2 - 1));
                                allPixelsToWrite.Add((pixel.Item1, pixel.Item2 - 1));}
                            }
                            else if (borderPos == BorderPosition.Outer)
                            {
                                if (pixel.Item1 + 1 < result.Height && !colorsToBorder.Contains(result.GetPixel(pixel.Item1 + 1, pixel.Item2)))
                                {
                                    nextPixels.Add((pixel.Item1 + 1, pixel.Item2));
                                    allPixelsToWrite.Add((pixel.Item1 + 1, pixel.Item2));
                                }
                                if (pixel.Item1 - 1 > 0 && !colorsToBorder.Contains(result.GetPixel(pixel.Item1 - 1, pixel.Item2)))
                                {
                                    nextPixels.Add((pixel.Item1 - 1, pixel.Item2));
                                    allPixelsToWrite.Add((pixel.Item1 - 1, pixel.Item2));
                                }
                                if (pixel.Item2 + 1 < result.Height && !colorsToBorder.Contains(result.GetPixel(pixel.Item1, pixel.Item2 + 1)))
                                {
                                    nextPixels.Add((pixel.Item1, pixel.Item2 + 1));
                                    allPixelsToWrite.Add((pixel.Item1, pixel.Item2 + 1));
                                }
                                if (pixel.Item2 - 1 > 0 && !colorsToBorder.Contains(result.GetPixel(pixel.Item1, pixel.Item2 - 1)))
                                {
                                    nextPixels.Add((pixel.Item1, pixel.Item2 - 1));
                                    allPixelsToWrite.Add((pixel.Item1, pixel.Item2 - 1));
                                }
                            }
                            else //Inner
                            {
                                if (pixel.Item1 + 1 < result.Height && colorsToBorder.Contains(result.GetPixel(pixel.Item1 + 1, pixel.Item2)))
                                {
                                    nextPixels.Add((pixel.Item1 + 1, pixel.Item2));
                                    allPixelsToWrite.Add((pixel.Item1 + 1, pixel.Item2));
                                }
                                if (pixel.Item1 - 1 > 0 && colorsToBorder.Contains(result.GetPixel(pixel.Item1 - 1, pixel.Item2)))
                                {
                                    nextPixels.Add((pixel.Item1 - 1, pixel.Item2));
                                    allPixelsToWrite.Add((pixel.Item1 - 1, pixel.Item2));
                                }
                                if (pixel.Item2 + 1 < result.Height && colorsToBorder.Contains(result.GetPixel(pixel.Item1, pixel.Item2 + 1)))
                                {
                                    nextPixels.Add((pixel.Item1, pixel.Item2 + 1));
                                    allPixelsToWrite.Add((pixel.Item1, pixel.Item2 + 1));
                                }
                                if (pixel.Item2 - 1 > 0 && colorsToBorder.Contains(result.GetPixel(pixel.Item1, pixel.Item2 - 1)))
                                {
                                    nextPixels.Add((pixel.Item1, pixel.Item2 - 1));
                                    allPixelsToWrite.Add((pixel.Item1, pixel.Item2 - 1));
                                }
                            }

                        }
                        currentPixels = nextPixels;
                        nextPixels = new List<(int, int)>();
                        if (borderPos == BorderPosition.Center) curRadius++;
                    }

                    foreach((int, int) pixel in allPixelsToWrite)
                    {
                        result.SetPixel(pixel.Item1, pixel.Item2, borderColor);
                    }
                }
            }
        }

        Bitmap result2 = new Bitmap(originalMap.Width, originalMap.Height);

        Graphics.FromImage(result2).DrawImage(result.Bitmap, 0, 0, originalMap.Width, originalMap.Height);

        result.Dispose();

        return result2;
    }