Fill color on specific portion of image?

Question

I want to fill specific color on specific area of an image.

EX:

Answer 1

You can Clip the context based on image Alpha transparency

I have created a quick image with black color and alpha

Then using the below Code

- (void)drawRect:(CGRect)rect
{
    CGContextRef context = UIGraphicsGetCurrentContext(); // Get the context
    CGContextSetFillColorWithColor(context, [UIColor blueColor].CGColor); // Set the fill color to be blue

    // Flip the context so that the image is not flipped
    CGContextTranslateCTM(context, 0, rect.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);

    // Clip the context by a mask created from the image
    UIImage *image = [UIImage imageNamed:@"image.png"];
    CGImageRef cgImage = image.CGImage;
    CGContextClipToMask(context, rect, cgImage);

    // Finally fill the context with the color and mask you set earlier
    CGContextFillRect(context, rect);
}

The result

This is a quick hint of what you can do. However you need now to convert your image to add alpha transparent to the parts you need to remove

After a quick search I found these links

How can I change the color 'white' from a UIImage to transparent

How to make one colour transparent in UIImage