UIImage+Tint.m

// code from https://gist.github.com/bigeyex/2d23202b6fdae3dfe004

#import "UIImage+Tint.h"

@implementation UIImage (Tint)
-(UIImage *)tintedImageWithColor:(UIColor *)tintColor {
    UIGraphicsBeginImageContextWithOptions(self.size, NO, [[UIScreen mainScreen] scale]);
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    CGContextTranslateCTM(context, 0, self.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);
    
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    
    // draw alpha-mask
    CGContextSetBlendMode(context, kCGBlendModeNormal);
    CGContextDrawImage(context, rect, self.CGImage);
    
    // draw tint color, preserving alpha values of original image
    CGContextSetBlendMode(context, kCGBlendModeSourceIn);
    [tintColor setFill];
    CGContextFillRect(context, rect);
    
    UIImage *coloredImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return coloredImage;
}
@end