I tried with the code below,
It works fine for me.
Code:
Public Function Highlight_Cell()
Set objExcel = CreateObject("Excel.Application")
objExcel.Visible = True
Set ObjWorkBook = objExcel.Workbooks.open (DataSheet_Path &"\" & "DWU.xls")
Set ObjWorkSheet = ObjWorkbook.WorkSheets("DS_Result")
For Each Cell In ObjWorkSheet.UsedRange
If Cell.Value = "False" Then
Cell.Interior.ColorIndex = 3
End If
Next
ObjWorkBook.Save
ObjWorkBook.close
Set objExcel = nothing
End Function
It works fine for me.