Minder Mindless

Okay so I'm trying to create a macro that creates a gradient map from a colour palette created from the photo inside the document and because I'm only trying to get the Highlights, midtones and shadows I need only three colours (as shown by photo of creating a colour palette from a normal photo) but i end up getting 68 and that's my issue. I have attached screenshots so as you can see what I'm talking about. Please respond if you have any feedback!