问更改快门动画iphone的颜色

EN

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self performSelector:@selector(makeRound) withObject:nil afterDelay:2.0];
}
-(void)makeRound
{
    [[[self.view viewWithTag:90] layer] setMasksToBounds:YES];
    [[[self.view viewWithTag:90] layer] setCornerRadius:75.0];
    [[[self.view viewWithTag:90] layer] setBorderWidth:2.0];
    [[[self.view viewWithTag:90] layer] setBorderColor:[[UIColor blackColor] CGColor]];
    [(UILabel *)[[self.view viewWithTag:90] viewWithTag:991] setText:@"Loading.."];
    [self shutter];
}
-(void)shutter
{
    CATransition *shutterAnimation = [CATransition animation];
    [shutterAnimation setDelegate:self];
    [shutterAnimation setDuration:1.5];
    [shutterAnimation setType:@"cameraIris"];
    [shutterAnimation setValue:@"cameraIris" forKey:@"cameraIris"];
    [shutterAnimation setRepeatCount:1];
    [[[self.view viewWithTag:90] layer] addAnimation:shutterAnimation forKey:@"cameraIris"];
}
-(void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
{
    [self performSelector:@selector(shutter) withObject:nil afterDelay:0.5];
}