When you read about Hans Hoffman's teaching, color was not used to copy nature literally, but to make relationships, mass and luminosity. Nature inspires but does not control. We, instead are in charge. Our choice of color is intuitive and expresses feeling.
You must consider that colors have look different depending on whether their edges are hard or soft. Whether the change in value at these edges is smooth or abrupt (as I experimented with above). The appearance of color is affected by the color adjacent. Simultaneous contrast is really what the relationships are all about.
Since I have returned home I am haunting my fields. As a compositional challenge I also purposely put that tree right in the middle. Heh.