Here are a few points to remember when painting on a sunny day:
The shadow side of an object is about 40% darker that the sun-lit side.
The sunny side is warmer in color temperature than the shady side.
The cast shadows are somewhat darker than the shadow side of the object.
Areas not affected by sunlight, such as holes and crevices, are usually warmer in color temperature.
The shadow side of an object contains reflected light, which adds interest and color. Reflected light is light thrown back on an object from another object.
The darkest dark in light is lighter than the lightest light in shadow.