|Gray Day Harmony 12x16 oil on linen panel|
You need to pay close attention to the light/dark contrasts. On a sunny day, the difference between shadow and sunlit areas can be as much as four value steps. There will be a dramatic difference in the appearance of a particular hue when seen in the light and shade. That difference accounts for wonderful color harmonies, with warm colors in the sunlight playing against cool, sky-lit colors in the shade. On a cloudy day, often there are no apparent shadows to work with, so values and color temperature needs to be closely observed. Also, atmospheric perspective plays a key role. Things in the foreground will appear much warmer, while distant colors become more muted and cooled by the veil of moisture in the air. Color, in general, can have a more uniformly saturated feel, being neither washed out by strong light or obscured by shadow, and grays play an important role as a foil to all the color. Is it blue-gray, violet-gray, greenish-gray…?
All that being said, there is something special, and moody feeling, about gray days. For me, they have a quiet, dignity, and a unified feel that resonates with inner peace and a more reflective frame of mind.