I am working with Images in Java, I have designed more over 100+ images(.png) format, They were all Trasparent and Black Color Drawing.

The problem is, Now I have been asked to change the color of the Drawing (Black -to ).

I have searched many code snipped at google,that changes the Bitmap (pixels) of the Image, but i am not guessing what i have to do to match the exact pixel and replace specially when the images if in Transparent mode.
Below is the code in .Net (C#) 

```
        Bitmap newBitmap = new Bitmap(scrBitmap.Width, scrBitmap.Height);
        for (int i = 0; i < scrBitmap.Width; i++)
        {
            for (int j = 0; j < scrBitmap.Height; j++)
            {                    
                originalColor = scrBitmap.GetPixel(i, j);
                if(originalColor = Color.Black)
                  newBitmap.SetPixel(i, j, Color.Red);
            }
        }            
        return newBitmap;

```

but it was not matching at all, I debugged it, throughout the file, there was no value of Red,Green,Blue parameters of Color (originalColor) variable.

Anybody can help?