diff --git a/app/src/main/java/view/MatrixPane.java b/app/src/main/java/view/MatrixPane.java
index f20ed0348c4905cb696c5158d80c6710e68109b7..85b0a674a23689cb92c5a121fd7a9bdbe718a1e5 100644
--- a/app/src/main/java/view/MatrixPane.java
+++ b/app/src/main/java/view/MatrixPane.java
@@ -8,6 +8,7 @@ import javafx.scene.layout.GridPane;
 import javafx.scene.paint.Color;
 import javafx.scene.shape.Rectangle;
 import javafx.util.Duration;
+import model.ArrayGrid;
 import model.Cell;
 import model.GrayGrid;
 import model.Grid;
@@ -28,8 +29,7 @@ public class MatrixPane extends GridPane {
         this.tileHeight = tileHeight;
         this.numberOfColumns = numberOfColumns;
         this.numberOfRows = numberOfRows;
-        // TODO replace by new ArrayGrid(numberOfRows, numberOfColumns)
-        cellGrid = new GrayGrid(numberOfRows, numberOfColumns);
+        cellGrid = new ArrayGrid(numberOfRows, numberOfColumns);
         initMatrix();
     }
 
diff --git a/app/src/test/java/model/SquareCellTest.java b/app/src/test/java/model/SquareCellTest.java
index 7551867da2d050faece42dfefbb507c0f558d82f..b33a5b070009121c484aad27b25b240b73c9e4e4 100644
--- a/app/src/test/java/model/SquareCellTest.java
+++ b/app/src/test/java/model/SquareCellTest.java
@@ -11,9 +11,6 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 class SquareCellTest {
 
-    // TODO
-    //  uncomment
-    /*
     private final Cell northCell = new SquareCell(Color.NAVY);
     private final Cell southCell = new SquareCell(Color.SALMON);
     private final Cell westCell = new SquareCell(Color.WHEAT);
@@ -51,5 +48,5 @@ class SquareCellTest {
         assertThat(centralCell.getNeighbours()).containsExactlyInAnyOrder(northCell,southCell);
     }
 
-     */
+
 }
\ No newline at end of file