Adding a class instance

I am trying to make a grid of images (like tic tac toe), and I am struggling on adding in an instance of my Tile class.

In my main game class, I am creating the grid using a loop. I am wanting to basically create a tile object for each spot in the grid, however there is no "new" keyword. I have been looking online and have come across a addComponent, but that only works with game objects, not images(i think).

Any possible ideas? I am still very new to Unity and how their code works.

Heres my two classes:

public class Grid : MonoBehaviour {

 public int numRows = 4;
 public int numColumns = 3;
 public Canvas gameCanvas;
 public Image tilePrefab;
 private int x = 300;
 private int y = 1500;

 void Start () {


     //Create the number of tiles needed
     Tile[] tiles = new Tile[numRows * numColumns];

     for (int i = 1; i <= tiles.Length; i++) {
         //tiles[i-1] = Instantiate(Tile) as GameObject;
         tiles[i-1].transform.SetParent(gameCanvas.transform);
         tiles[i-1].transform.position = new Vector3 (x, y, 0f);
         x += 320;

         if (i % 3 == 0) {
             x = 300;
             y -= 320;
         }
     }
 }

and the tile class:

public class Tile : MonoBehaviour {

 public Image tilePrefab;

 private Color[] colors = new Color[4];

 void Start () {
     //Different colors the tile can be
     colors[0] = new Color(242, 103, 103); //Pink
     colors[1] = new Color(80, 206, 196); //Blue
     colors[2] = new Color(147, 206, 80); //Green
     colors[3] = new Color(238, 174, 79); //Orange

     //Creates the tile image
     Image tile = Instantiate(tilePrefab) as Image;
     tile.color = colors [Random.Range (0, colors.Length)];


 }