Experiments in Color Harmony

The path from a plein air sketch to a finished, studio painting isn't always obvious.  Whenever I'm in doubt about my route, I do a little scouting.  For example, where would I go with the following sketch?

My Backyard 9x12 oil study

I would make two observations about it.  First, when I review my memory of the scene, I know the sketch captures the color and value relationships accurately.  Second, the design is, unfortunately, cluttered and claustrophic.  Attacking the design would be my first step.  As for a second step—what if I played with the color scheme while making an effort to keep the color and value relationships true?  Could I come up with more exciting color?

In a recent workshop, I worked with a student to explore just this question.  Using the above plein air reference, we made four small studies with different color schemes.  Our goal was to maintain the "truth" of the moment, which is about strong sunlight.

We didn't think it necessary to paint the whole scene over and over.  Instead, we restricted our experiment to a small area, making sure that it included a place where major shapes touched, and we "posterized" the scene to simplify the shapes.  Once the experiment was complete, we could then take the solution to the rest of the painting.  Here's the area we chose to experiment with:

My Backyard 9x12 oil study- detail

As for evoking a sense of sunlight, I'm a big believer in using complements and near-complements to give tonal contrast a boost.  So, we took a 12x16 panel and divided it into four rectangles, and for each rectangle chose a different pair of complementary colors (or near-complementary) and also added a touch of what I call a "spice color."  We made good use of a color wheel to identify complements and near-complements.  Spice colors came from somewhere between the two colors in the pair.

Here are the results:

Going clockwise, from upper left, the colors are:

A: Shadow:  dull purple and blue / Light: yellow / Spice colors: red, green
B: Shadow:  green and yellow-green / Light: magenta / Spice colors: yellow, red
C: Shadow: dull red and dull purple / Light: blue / Spice color: green
D: Shadow: magenta and blue / Light: yellow / Spice colors: green, red.  (This experiment we intentionally made in a high-key.)

For pigments, I used the following Gamblin colors:  hansa yellow light, hansa yellow deep, napthol scarlet, permanent alizarin crimson, quinacridone magenta, ultramarine blue and phthalo green.

Which do you feel is the most successful experiment?  The least?