Local color is the middle color and value that you see when you look at an object. For instance, a bunch of cherries would have the basic local color of deep red. All variations within the light and shadow sides of that form, according to this way of painting, are created by deepening or lightening, warming or cooling, or greying the intensity of that basic red. This is useful to know, but shouldn’t be used to limit what you see when you paint.
You can demonstrate the above definition by doing some sample exercises using common fruit. For instance: draw the outline of an orange. Find the "local Color". Then darken (with it’s complement, blue) the side that is in shadow. Now lighten and warm the side that is toward the light with light orange or yellow. (You can vary the colors used to lighten and darken the form according to whether the light hitting the object is warm or cool.)
Try this exercise on a number of different simple colored objects like fruit or blocks or boxes. Keep it simple. Keep some of the Local Color showing.
Select five objects of various shapes and sizes with different home values and arrange them in a group. Avoid lining up objects evenly in a row. Overlap things. Stack one object on top of another. Turn a form on its side or even upside down. Begin painting the whole group. Start by painting it as a mass, using a middle grey or brown tone. Focus on the overall compositional shape. Keep the background simple. Then begin to separate the objects by painting in the darks and lights from the middle tone.