Eye Dropper Tool

I am trying to create a 2d faceme scale model but cant seem to figure out how to use eye dropper tool to select the color from the image I imported to paint on the respective surfaces of my model. When I use the ED tool it samples the entire image and paints the surface with the entire photo, not the specific color I am trying to sample in the photo.
How do you sample a specific color from an imported image?

You need to add some colors to the In Model materials and then edit them using the Match Color on Screen tool to change the colors to what you want. Like this.

Thank you