UIPopoverController is not so with a color - ios

Question

Does anyone know why is appearing white part? My View is already gray, but gets two white pieces
whites: Arrow and final Popover!
[UPDATE]
this is the code that calls the popover and makes the arrow points to the button that was clicked!
- (void) buttonFilter {
if (viewFilter == #"Artistas") {
content = [self.storyboard instantiateViewControllerWithIdentifier:#"TipoArtistaViewController"]; // MUDAR PARA O NOVO FILTRO DE ARTISTAS
} else if (viewFilter == #"Músicas") {
content = [self.storyboard instantiateViewControllerWithIdentifier:#"CategoriaViewController"];
}
[self callFilter:btnFilter Filter:content];
}
- (void)callFilter:(id)sender Filter:(UIViewController *) content{
self.currentPop = popoverController;
popoverController = [[WYPopoverController alloc] initWithContentViewController:content];
UIButton * bt = (UIButton * )sender;
UIView *view = [bt valueForKey:#"view"];
popoverController.popoverContentSize = CGSizeMake(320, 180);
popoverController.delegate = self;
[popoverController presentPopoverFromRect:view.bounds inView:view permittedArrowDirections:WYPopoverArrowDirectionAny animated:YES];
}
the next is where to mount the session:
//extend and collpase
- (void)setupViewController {
categoriaBD = [categoriaDAO selectCategoria];
self.data = [[NSMutableArray alloc] init];
for (int i = 0; i < [categoriaBD count]; i++)
{
NSMutableDictionary * teste = [categoriaBD objectForKey:[NSString stringWithFormat:#"%i", i]];
ID = [[teste objectForKey:#"1"] integerValue];
subcategoriaBD = [categoriaDAO selectSubCategoriaByCategoriaID:ID];
NSMutableArray* section = [[NSMutableArray alloc] init];
for (int j = 0; j < [subcategoriaBD count]; j++)
{
NSMutableDictionary * subCat = [subcategoriaBD objectForKey:[NSString stringWithFormat:#"%i", j]];
[section addObject:[NSString stringWithFormat:[subCat objectForKey:#"1"]]];
}
[self.data addObject:section];
}
self.headers = [[NSMutableArray alloc] init];
for (int i = 0; i < [categoriaBD count]; i++)
{
NSString *inStr = [NSString stringWithFormat: #"%i", (int)i];
nomeCategoria = [categoriaBD objectForKey:inStr];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(5, 5, 310, 40)];
[label setText:[nomeCategoria objectForKey:#"2"]];
UIView* header = [[UIView alloc] init];
[header setBackgroundColor:[UIColor colorWithRed:(226/255.0) green:(226/255.0) blue:(226/255.0) alpha:1]];
[header addSubview:label];
[self.headers addObject:header];
}
}

Answer 1

You can to create a custom UIPopoverBackgroundView subclass that sets the properties of the arrow you want.
popoverController.popoverBackgroundViewClass = [MyPopoverBackgroundView class];