Set Background for Tabbar Item Active and change color certain item:

tabbarItem.m

  NSInteger numberOfItems = self.tabBar.items.count;
    CGSize tabBarItemSize = CGSizeMake(self.tabBar.frame.size.width / numberOfItems, self.tabBar.frame.size.height);
    self.tabBar.selectionIndicatorImage = [UIImage imageWithColor:[UIColor colorWithHexString:@"#040A0F" ] size:tabBarItemSize];
    
 
    NSInteger itemIndex = 2;
    
    
    CGFloat itemWidth = self.tabBar.frame.size.width / numberOfItems;
    
    UIView *bgView = [[UIView alloc] initWithFrame:CGRectMake(itemWidth * itemIndex, 0, itemWidth, self.tabBar.frame.size.height)];
    bgView.backgroundColor = [UIColor colorWithHexString:@"#BB0002"];
    [self.tabBar insertSubview:bgView atIndex:0];