How I can set pixel in the Shape with the specific RGB?

For example, I have a polygon and I need to fill it with the specific RGB. How can I do it? I tried to convert shape to image, but then I can't set a pixel with setRGB method from BufferedImage(pixel color wasn't changing!):

...
    Rectangle2D r = pgnProjection.getBounds();
    BufferedImage rectBuffIm = new BufferedImage(r.getBounds().width, r.getBounds().height, 
                                        BufferedImage.TYPE_BYTE_BINARY);
    for(int i = rectBuffIm.getWidth()/2, j = rectBuffIm.getHeight()/2; rectBuffIm.getWidth()>i && rectBuffIm.getHeight()>j; j++, i++)
        rectBuffIm.setRGB(i, j, rgb);

    Graphics2D gr2D = rectBuffIm.createGraphics();
    gr2D.translate(-pgnProjection.getBounds().x, -pgnProjection.getBounds()开发者_如何学C.y);
    gr2D.draw(pgnProjection);
    gr2D.dispose();
...

Also, image background was black, and set pixels were always white.

Call Graphics.setClip(Shape) followed by the drawing operations. See here for an example.

Graphics.fillPolygon()