hole card

I have never been a card player, however one “hole card” that is no longer a secret with me, I would like to share with you.  I learned this trick from an incredible teacher that I took art lessons from way back while in High School here.  If we were painting from a photograph, one tool that we learned to use was to simply “hole punch” a card and place it over the color that you were trying to see and “voila” you would somehow have a sort of “gps” to find the color.