This week we're making cards showing at least three forms of color.  For example:  We might have a warm blue, a cool blue and the true blue. 
If there are cards showing each color and its variations it becomes easier to make choices when we go to the actual painting.
For example:  If we have an apple.  We would first look at the value of the apple and do a value sketch.  Then we would look at the relative temperature of areas on the apple.  The areas where the light hits would be warmer than the areas in shadow.

By using the color charts you have been working with, you might choose a warm, light (high key) color for the sun-exposed areas, and a cool, dark (low key) color for the shadows.  In this way an apple becomes more than a dark red and light red composition, and may contain  It becomes something very exciting!