Remove Top Bar of Collection View - uicollectionview

Question

I have a small emoji collection view that is displayed when users tap an emoji button. I would like to get rid of the top bar space so that the background, for example, is all blue. I tried making top bar on storyboard None.. How can I remove this space?
import UIKit
class EmojiViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate {
let emojiImages = [...the pics...]
var selectedIndex: Int?
var estimateWidth = 100.0
var cellMarginSize = 10.0
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return self.emojiImages.count
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "emojiCell", for: indexPath) as! EmojiViewCell
let emoji = emojiImages[indexPath.row]
cell.emojiImage.image = UIImage(named: emojiImages[indexPath.row])
if selectedIndex == indexPath.row {
cell.backgroundColor = UIColor.red
self.dismiss(animated: true, completion: nil)
UserDefaults.standard.set(emoji, forKey: "emojiPicked")
}else{
cell.backgroundColor = UIColor.clear
}
return cell
}
func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
selectedIndex = selectedIndex == indexPath.row ? nil : indexPath.row
collectionView.reloadData()
}
}
extension EmojiViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return CGSize(width: 40, height: 40)
}
}