How do I change the navigation bar background in a UICollectionView - ios6

Question

I have a project with a dozen different view controllers. All use the same code to set the background of their navigation bars as follows:
CGRect frame = CGRectMake(0, 0, [self.title sizeWithFont:[UIFont fontWithName:#"HelveticaNeue" size:28]].width, 44);
UILabel *titleLabel = [[UILabel alloc] initWithFrame:frame];
titleLabel.text = #"Categories";
titleLabel.font = [UIFont fontWithName:#"HelveticaNeue" size:22];
titleLabel.backgroundColor = UIColorFromRGBWithAlpha(0x84A537, 0.5);
titleLabel.textAlignment = NSTextAlignmentCenter;
self.navigationItem.titleView = titleLabel;
self.navigationController.navigationBar.tintColor = UIColorFromRGBWithAlpha(0x84A537, 0.5);
self.navigationItem.titleView.backgroundColor = [UIColor clearColor];
self.navigationController.view.backgroundColor = UIColorFromRGBWithAlpha(0x84A537, 0.1);
They all work fine, except for the CollectionView where the title text has a grey background. I've copied and pasted the code from other VCs. I don't know what I'm doing to cause this. I set the color hex values like this:
//RGB color macro
#define UIColorFromRGB(rgbValue) [UIColor \
colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
blue:((float)(rgbValue & 0xFF))/255.0 alpha:1.0]
//RGB color macro with alpha
#define UIColorFromRGBWithAlpha(rgbValue,a) [UIColor \
colorWithRed:((float)((rgbValue & 0xFF0000) >> 16))/255.0 \
green:((float)((rgbValue & 0xFF00) >> 8))/255.0 \
blue:((float)(rgbValue & 0xFF))/255.0 alpha:a]

Answer 1

It seems that the navigation bar style settings for Collection views are different from other view controllers. For these, I had to set the bar color in the calling controller, and set the nav. bar background color in the collection view to clearColor.
I hope this helps others.
calling VC:
- (IBAction)imageButtonTapped:(id)sender {
imageCellLayout = [[ImageCellLayout alloc] init];
imageViewController= [[ImageViewController alloc] initWithCollectionViewLayout:imageCellLayout];
imageViewController.item = item;
addImageViewController.item = item;
imageViewController.collectionView.pagingEnabled = YES;
UINavigationController *nc = [[UINavigationController alloc] initWithRootViewController:imageViewController];
nc.navigationBar.tintColor = UIColorFromRGBWithAlpha(0xC43F32, 0.5);
nc.modalPresentationStyle = UIModalPresentationPageSheet;
[self presentViewController:nc animated:YES completion:nil];
}
collection view:
//Title Stuff
CGRect frame = CGRectMake(0, 0, [self.title sizeWithFont:[UIFont fontWithName:#"HelveticaNeue" size:28]].width, 44);
UILabel *titleLabel = [[UILabel alloc] initWithFrame:frame];
NSString *tempTitle = item.title;
titleLabel.text = tempTitle;
titleLabel.font = [UIFont fontWithName:#"HelveticaNeue" size:22];
titleLabel.backgroundColor = [UIColor clearColor];
titleLabel.textAlignment = NSTextAlignmentCenter;
self.navigationItem.titleView = titleLabel;