How to save sprite color change on custom inspector ?

CLass code :

using UnityEngine; using System.Collections;

 //[ExecuteInEditMode]
 //[System.Serializable]
 public class TileData : MonoBehaviour {
     
 
     //    public Color color;
 
     public SpriteRenderer spr;
 
     //[SerializeField]
     public enum Type 
     {
         clear,
         building,
     }
     //[SerializeField]
     public Type type;
     public bool guarded;
     public Color buildingColor;
     public Color clearColor;
 
     public void ChangeType()
     {
         switch (type) 
         {
         case Type.building :
             spr.color = buildingColor;
             
             break;
         case Type.clear :
             spr.color = clearColor;
             break;
         }
 
     }
 
 }
 

And custom inspector :

 using UnityEngine;
 using System.Collections;
 using UnityEditor;
 
 [CanEditMultipleObjects,CustomEditor(typeof(TileData))]
 public class tileEditor : Editor {
 
     //Color color = new Color();
 
     public override void OnInspectorGUI()
     {
 
         DrawDefaultInspector();
         TileData tileDataScript = (TileData)target;
 
         
         if(GUI.changed)
         {
             //EditorUtility.SetDirty(target);
             //EditorUtility.SetDirty(tileDataScript);
 
             tileDataScript.ChangeType();
             SceneView.RepaintAll();
             
         }
         if(GUILayout.Button("update"))
         {
             tileDataScript.ChangeType();
             SceneView.RepaintAll();
         }
 
 }
 }

So i just want some script to only be executed in the editor. So i created a custom editor. When i enter play mode everything is saved except the color of my sprites which reset to default. I can't figure out how to save the color change. Can someone help me ?

EDIT : So it seems that every change i make on my spriteRenderer spr ( child of my prefab assigned manually in the inspector) is not saved.