Private Sub Worksheet_Change(ByVal Target As Range)
Application.EnableEvents = False
Set zone = ActiveSheet.Range("C3:C" & (Range("C" & Rows.Count).End(xlUp).Row))
If Not Intersect(Target, zone) Is Nothing Then
For Each ele In zone
If ele.Interior.ColorIndex <> xlColorIndexNone Then
[O4] = ele
End If
Next ele
End If
Application.EnableEvents = True
End Sub