Hi Jocelyn,

 
 Here are the sample code that I made to change a text color of the edited cell with a validation and an alert to show the original value from the client side of onExitEditMode. I hope it can help.

 <script language="javascript" type="text/javascript" id="WebGrid1_OnExitEditMode_1">
  <!--
  function WebGrid1_OnExitEditMode_1(controlId, tblName, editObject)
  {
   var WebGrid1 = ISGetObject(controlId);
   
   var cellObject = editObject.ToCellObject();

   var selectedValue = cellObject.Value;

   if (selectedValue <= 10){

       cellObject.CellElement.style.color = "Red";

   }

   alert("Old Value is " + selectedValue); 
     
   return true;
  }
  -->
</script>

Thank you,
Andi Santoso