Detect if colors are matched

Question

I am trying to detect if colors are matched (2x2) in Unity2D, but it doesn't fully work. I have 16 tiles with 4 different colors. I am detecting if the colors are matched with a script, which is attached to each collider which collides with 4 tiles around it. In front of each colider is a button, which rotates the 4 tiles around that button (collider) to the right. The scripts of the colliders have a list called childTiles. The list contains the 4 tiles around that collider, to detect if there are 4 tiles of the same color in one list. It looks like this. (GIF) https://gyazo.com/a2a5c8a5051e937338807fb5ecfaa4ec

This script is attached to each collider. There are 9 colliders in total (each one behind a button).

public GameObject GameManager;

public List<GameObject> ChildTiles = new List<GameObject>();
public GameObject[] ParentPositions;
//public GameObject Tiles;
public bool canTurn = true;
private TileController parentPositions;
private float _rotationDegrees;
private GameManager gameManager;

public Color Green;
public Color Red;
public Color Blue;
public Color Yellow;
public bool greenComplete = false;
public bool redComplete = false;
public bool blueComplete = false;
public bool yellowComplete = false;

public GameObject Topleft; //colliders (only these colliders are necessary out of the 9)
public GameObject Topright;
public GameObject Bottomleft;
public GameObject Bottomright;

public GameObject tileGreen1;
public GameObject tileRed1;
public GameObject tileBlue1;
public GameObject tileYellow1;

void Awake()
{
    if (gameObject.name == "Top-left" || gameObject.name == "Top-right" || gameObject.name == "Bottom-left" || gameObject.name == "Bottom-right")
    {
        Green = tileGreen1.GetComponent<SpriteRenderer> ().color;
        Red = tileRed1.GetComponent<SpriteRenderer> ().color;
        Blue = tileBlue1.GetComponent<SpriteRenderer> ().color;
        Yellow = tileYellow1.GetComponent<SpriteRenderer> ().color;
    }
    GameManager = GameObject.Find ("GameManager");
    //Tiles = GameObject.Find ("Tiles");
    ParentPositions = GameObject.FindGameObjectsWithTag ("Position");
}

void Update()
{
    greenComplete = parentPositions.greenComplete;
    redComplete = parentPositions.redComplete;
    blueComplete = parentPositions.blueComplete;
    yellowComplete = parentPositions.yellowComplete;
}

void Start()
{

    gameManager = GameManager.GetComponent<GameManager> ();
    _rotationDegrees = 0f;
    foreach (GameObject go in ParentPositions) 
    {
        parentPositions = go.GetComponent<TileController> ();
    }
}


public void SquareClicked()
{
    if (parentPositions.canTurn == true && gameManager.turns > 0f)
        {
        gameManager.turns -= 1;
        gameManager.turnsText.text = "Turns: " + gameManager.turns;
        foreach(GameObject go in ParentPositions)
        {
            parentPositions = go.GetComponent<TileController> ();
            parentPositions.canTurn = false;
        }

        foreach(GameObject tile in ChildTiles)
        {
            tile.transform.parent = gameObject.transform;
        }
        StartCoroutine(Rotate()); //this is where you do the rotation of the parent object.

        if (gameManager.turns == 0f) 
        {
            gameManager.turnsText.text = "No turns left";
        }
    }
}

IEnumerator Rotate()
{
    LeanTween.rotateZ (gameObject, _rotationDegrees - 90f, 0.5f);
    _rotationDegrees -= 90f;
    if (_rotationDegrees == -360f) 
    {
        _rotationDegrees = 0f;
    }
    yield return new WaitForSeconds (0.5f);
    parentPositions.canTurn = true;

    yield return new WaitForSeconds (0.5f);
    if (parentPositions.greenComplete == false) 
    {
        parentPositions.greenComplete = parentPositions.ChildTiles.All (t => t.GetComponent<SpriteRenderer> ().color == Green);
    }
    if (parentPositions.redComplete == false) 
    {
        parentPositions.redComplete = parentPositions.ChildTiles.All (t => t.GetComponent<SpriteRenderer> ().color == Red);
    }
    if (parentPositions.blueComplete == false) 
    {
        parentPositions.blueComplete = parentPositions.ChildTiles.All (t => t.GetComponent<SpriteRenderer> ().color == Blue);
    }
    if (parentPositions.yellowComplete == false) 
    {
        parentPositions.yellowComplete = parentPositions.ChildTiles.All (t => t.GetComponent<SpriteRenderer> ().color == Yellow);
    }

    Debug.Log ("_greenComplete " + parentPositions.greenComplete);
    Debug.Log ("_redComplete " + parentPositions.redComplete);
    Debug.Log ("_blueComplete " + parentPositions.blueComplete);
    Debug.Log ("_yellowComplete " + parentPositions.yellowComplete);

    if (parentPositions.greenComplete && parentPositions.redComplete && parentPositions.blueComplete && parentPositions.yellowComplete) 
    {
        Debug.Log ("Level Complete");
    }

}

void OnTriggerEnter2D(Collider2D col)
{
    if (col.gameObject.tag == "Tile") 
    {
        ChildTiles.Add (col.gameObject);
    }
}

void OnTriggerExit2D(Collider2D col)
{
    if (col.gameObject.tag == "Tile") 
    {
        ChildTiles.Remove (col.gameObject);
    }
}

As you can see in the GIF, there is a problem. The problem is that when there are 4 colors matched, it doesn't return True. It only returns True if you click a button with 4 tiles of the same color around it. Only then it returns True. So you match 4 colors, it doesn't return True, you click the button with those 4 colors around it, it returns True. How do I make it so that it immediately returns True, if 4 colors are matched? As you can see I only use the top-left, top-right, bottom-left and bottom-right collider, as these are the only possible colliders to have 4 tiles with the same color in them at the same time.