FadeIn

using System.Collections;

public class FadeInWithPanel : MonoBehaviour {

	public float fadeInTime;

	private Image fadePanel; 
	private Color currentColor;

	public int stayTime = 1;

	void Start (){
		currentColor = Color.black;
		fadePanel = GetComponent<Image> ();
	}

	void Update (){
		if (Time.timeSinceLevelLoad < stayTime) {
			currentColor = Color.black;
		}
		else {
			float alphaChange = Time.deltaTime / fadeInTime;
			currentColor.a -= alphaChange;
			fadePanel.color = currentColor;
		} if (Time.timeSinceLevelLoad > fadeInTime + stayTime) {
			gameObject.SetActive (false);
		}
	}
}