Apply color to black-masked-image

applyColorToImage.m

// pass color & supply masked (masked with black-color) image
+ (UIImage *)applyColor:(UIColor *)color toImage:(UIImage*)toImage{
    // create context
    UIGraphicsBeginImageContextWithOptions(toImage.size, NO, toImage.scale);
    
    // get context reference
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    // Change the origin of the user coordinate system in a context.
    CGContextTranslateCTM(context, 0, toImage.size.height);
    
    // Change the scale of the user coordinate system in a context.
    CGContextScaleCTM(context, 1.0, -1.0);
    
    // Set how blend-normal for a graphics context.
    CGContextSetBlendMode(context, kCGBlendModeNormal);
    
    // get region of rect
    CGRect rect = CGRectMake(0, 0, toImage.size.width, toImage.size.height);
    
    // Create gradient - (but we have single color here)
    NSArray *colors = [NSArray arrayWithObjects:(id)color.CGColor, (id)color.CGColor, nil];
    CGColorSpaceRef space = CGColorSpaceCreateDeviceRGB();
    CGGradientRef gradient = CGGradientCreateWithColors(space, (__bridge CFArrayRef)colors, NULL);
    
    // Apply gradient to mask
    CGContextClipToMask(context, rect, toImage.CGImage);
    CGContextDrawLinearGradient(context, gradient, CGPointMake(0,0), CGPointMake(0, toImage.size.height), 0);
    UIImage *coloredImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    
    CGGradientRelease(gradient);
    CGColorSpaceRelease(space);
    
    return coloredImage;
}