Change the background color of an object when clicked.

In PowerPoint 2013 I have a very simple setup where on one slide I need the fill color of a circle to change when clicked. I would use animations, but I need the changed color to persist even when navigated away from and back. The user will be using this as a tutorial and will need to be able to flip through at will. There will be several of these buttons on this one slide which makes adding dummy slides with the changed color unworkable (there are too many combinations).

For simplicity, I have renamed the circle A1. My code so far is:

Dim S1 as Shape
Sub ChangeColorA1()
Set S1 = ActivePresentation.Slides(35).Shapes("A1")
With S1
  .Fill.ForeColor.RGB = RGB(104, 174, 226)
End With
End Sub

The issue with this is that the slide does not refresh when the circle is clicked. When you exit the slideshow, the circle is the new color in the editor, but during the show the fill does not change.

I don't want to add to much complexity, but how do you get the slide to refresh during the presentation?