Changing Backcolor between form and subform

[Talen]

I am trying to change the backcolor of the fields on enter and on exit so that the user knows what field is selected. I have this working fine within the form and within the subform. However, when I am in the subform and click on a field in the main form, the field in the subform remains highlighted - while also highlighting the new field that I have selected. I have also tried setting the subform fields exit event to trigger on lost focus instead but it still does the samething.

Any help would be greatly appreciated.