The wheel above is free to the public, and it shows the concept of a use of color in astrology.  This concept involves one color per each of the 12 Houses.  This results in one color for each House "trilogy" (i.e. of the House itself, of the ruling zodiac sign of the House, and the planet(s) or luminary that rules the sign which rules the House). Per my analysis, there are two "yin-yang" formations (Sun-Moon and Jupiter-Saturn) and three harmonic "trees" (which are Mercury-Chiron-Uranus, Venus-Neptune, and Mars-Pluto). Let's review these trees first, and conclude with the "yin-yang" formations.

The color blue is used above to depict the harmonic vibrations of Mercury, Chiron, and Uranus. There is a spirit of "investigation" and "a need to find answers to questions " with these three planets. Notice that Mercury and Chiron are very close to the same shade of navy blue, but Chiron is a little lighter navy blue (and this light intensity of navy blue may be due to Mercury ruling two signs, while Chiron rules only one of the two signs ruled by Mercury [which happens to be Virgo. Mercury also rules Gemini]). Both Mercury and Chiron "flow" to Uranus, which is the lightest of the blue color. Uranus rules aspirations and intellectual breakthroughs, and Mercury and Chiron may play a role with manifestation of aspirations and intellectual breakthroughs.

The color green is used above to depict the harmonic vibration between Venus and Neptune.  Appreciation of beauty in the environment is a similar theme with both planets. Venus may call for involvement with activities that help society, and Neptune may call for "escape" from society in some way.  Both planets have a "service" element to them, but Venus is often more of a manager or advisor and may not care for some of the services of Neptune (which may explain why Venus is a lighter shade of green).

Mars and Pluto (above) appear to share shades of red, which can define the vibration of action.  With Mars, the action is more public. With Pluto, the action is more private or secretive (and with Mars, there are more risks since actions are open and public. This may explain why Mars is a darker red color). There is also an element of "competition" with both planets, with Pluto again showing a hidden or occult side regarding competitive activities (while Mars is more open, and again, subject to risks). 

Above are the two "yin - yangs,"  which are Sun-Moon (of course) and Jupiter-Saturn.  Sun-Moon is a part of the personality complex, with the Sun representing the personality seen by the public and the Moon representing the personality seen only by family or those "like family." Jupiter-Saturn is a yin-yang type of energy that concerns Jupiter non-duty action (i.e. "adventure") versus the required duty action of Saturn.  And yes, Jupiter rules "expansion" while Saturn rules "restrictions." The Sun-Moon and Jupiter-Saturn pairs are two yin-yang types of astrology energy complexes. Please note that the components of these two pairs do not share the same harmonic vibrations with the other point that it is being paired with. 

Thanks for reading.

Love to all,

Malcolm