how to fill color in image in particular area?

Here's a quick application using Python and OpenCV (should be available on Android if you try hard enough):

"""Flood fills with random color on click.  Press `q' to exit."""
import cv
import sys
import random

TOL = 10
TOL_BGR = (TOL, TOL, TOL, 0)

def click(event,x,y,flags,im):
    if event == cv.CV_EVENT_LBUTTONDOWN:
        b,g,r = [ random.random() * 255 for i in range(3) ]
        cv.FloodFill(im, (x,y), (b,g,r,0), TOL_BGR, TOL_BGR)

im = cv.LoadImage(sys.argv[1], cv.CV_LOAD_IMAGE_COLOR)
cv.NamedWindow(__file__, 1)
cv.SetMouseCallback(__file__, click, im)
while True:
    cv.ShowImage(__file__, im)
    key = cv.WaitKey(33)
    if chr(key & 0xff) == 'q':
        break
cv.SaveImage('floodfill.png', im)

Every time the user clicks an image, the application flood-fills using the click location as a seed. The color is picked randomly. You can change the tolerances by modifying the value of TOL (or TOL_BGR). Here's the result after a couple of clicks:

The general algorithm is the same regardless of what technology you use.

I found the Solution with Flood fill algoritham

private void FloodFill(Bitmap bmp, Point pt, int targetColor, int replacementColor){
Queue<Point> q = new LinkedList<Point>();
q.add(pt);
while (q.size() > 0) {
    Point n = q.poll();
    if (bmp.getPixel(n.x, n.y) != targetColor)
        continue;

    Point w = n, e = new Point(n.x + 1, n.y);
    while ((w.x > 0) && (bmp.getPixel(w.x, w.y) == targetColor)) {
        bmp.setPixel(w.x, w.y, replacementColor);
        if ((w.y > 0) && (bmp.getPixel(w.x, w.y - 1) == targetColor))
            q.add(new Point(w.x, w.y - 1));
        if ((w.y < bmp.getHeight() - 1)
                && (bmp.getPixel(w.x, w.y + 1) == targetColor))
            q.add(new Point(w.x, w.y + 1));
        w.x--;
    }
    while ((e.x < bmp.getWidth() - 1)
            && (bmp.getPixel(e.x, e.y) == targetColor)) {
        bmp.setPixel(e.x, e.y, replacementColor);

        if ((e.y > 0) && (bmp.getPixel(e.x, e.y - 1) == targetColor))
            q.add(new Point(e.x, e.y - 1));
        if ((e.y < bmp.getHeight() - 1)
                && (bmp.getPixel(e.x, e.y + 1) == targetColor))
            q.add(new Point(e.x, e.y + 1));
        e.x++;
    }
}}

flood fill in android:

See this FloodFill