Understanding how light effects our lives begins with an understanding of the relationship between human qi and the electromagnetic spectrum that makes up the visible colors.
Life has evolved on this planet under the influence of our sun. So it is that our emotions, our mental states, and our health, are influenced by the colors found in sunlight. When photons of light strike matter, electrons are discharged, thus creating a current. In other words, the energy of light is converted into electrons on impact and "the frequency of radiation determines the energy of the electrons emitted,"  and consequently the quality of the qi we take in through color and light.
European medical researchers have discovered that pulsed and colored light focused on the iris of the eye will prompt both physical and emotional repair in the body. Light reaching the eye is converted into electrical signals that are transmitted by the optic nerve to the hypothalamus, which regulates all of our biological functions by controlling the nervous system and the endocrine system. "In addition, the hypothalamus controls most of the body's regulatory functions by monitoring light related information and sending it to the pineal, which then uses this information to cue other organs about light conditions in the environment." In simpler terms, the pineal gland is a type of light regulator for the body, and since "wavelengths of light control the chemistry of the body," the various color changes we make in our home and working spaces by applying feng shui wisdom have a powerful affect on our emotions and sense of well-being through their physiological, psychological and hormonal impact.
In addition, the influence of light and color also may coincide with the taking in of another type of energy: the Qi of Heaven—the energy of the sun, moonlight, and the stars.
In Oriental medicine, we say that the human being is created when the Qi (energy) of Heaven and the Qi of Earth come together.
In Oriental medicine, we say that the human being is created when the Qi (energy) of Heaven and the Qi of Earth come together. I postulate that the Qi of Heaven continues to enter the formed human body through the pineal organ in the form of light.
Another entrance point for Qi of Heaven in the form of light is through the acupuncture point/meridian system of the body. Russian researchers have shown that light applied to the human skin penetrates between 2 and 30 mm, depending on the color spectrum or frequency of light used, and that it will travel beneath the surface of the skin. According to their findings, the meridians, which are the channels for qi, act like optical fibers in transferring light (photons) throughout the body. This would explain why blind people can "feel" colors and also why light travels beneath the surface of the skin even when body parts are twisted or bent. This transport of light through the meridian system dovetails with the ancient Chinese medical model and would explain the ability of light entering the body in this way to trigger healing at a cellular level. Each cell has transport tubes known as microtubules or "light pipes" which are of varying widths and lengths measured in nanometers that allow the movement of molecules and fluid in and out of the cell. As a further part of the light transport system that starts with the acupoints and meridians, these "microtubules…may act like fiber optic waveguides for the transmission of light waves through us." The light that travels from these energy pathways to the level of the cells may act as an aspect of qi that allows cells to communicate to each other the information that is important to the healing process; yet another important reason for attention to the use of balanced lighting in the feng shui applications in our homes and workplaces. To have health in the body there needs to be coherence to establish healthy cell communication.
Here is a very fundamental example of the "hidden" energies or qi behind feng shui for what is actually at work here is quantum physics. In quantum physics, subatomic particles are coherently linked by magnetic fields so they can communicate together, thus creating resonance. In addition to the quantum coherence involving cells and light, Dr. Fritz-Albert Popp discovered that we take in biophotons from the plant foods we eat. The better the quality of the qi or light in the food we take in that was absorbed during its growth, the more light we take in that was stored during photosynthesis.]
Popp also discovered that the driving force behind our DNA was light. He found that DNA was one of the most essential stored sources of light and thus the one of the main sources of biophoton emissions. It was the master tuning fork of the body, using light frequencies to produce the blueprint for the human body and all living things. This is the case also at the fundamental level of light photons that Popp discovered in his experiments both cancer patients and those with multiple sclerosis (MS). There was a fundamental imbalance of light. In those with cancer, it was as if their light was going out. Frequencies were scrambled and cells had lost their connection with each other and other living things out in the world. In those with MS, it was as if they were drowning in too much light. Cells could not reject excess light to stay balanced as they would in a healthy state. This ability of human cells to produce bioluminescence or the giving off of light to stay balanced was actually measured by Popp in his experiments. He was able to show that eggs from free-range chickens raised under sunlight had taken in better qi or coherent light photons than those eggs produced by chickens raised under artificial lighting. He was able to measure the quality of all food using his bio-photon method. He discovered that "the healthiest food had the…most coherent intensity of light" and that "health was a state of perfect subatomic communication, and that ill health was a state where communication breaks down. In effect, we are ill when our light waves are out of synch. The work of Fritz-Albert Popp gives support to the great importance of light in feng shui balancing in our daily environments. His further experiments showed that we can take the photons of light from our surroundings (and especially living things in our surroundings), and "use the information from them to correct our own light" if it goes out of balance.
One of these ways would be the use of color as it is applied in feng shui. Another would be through eating the proper foods. The color of food tells us about the energetic signature (qi) of that food. It is Nature's way, through her beautiful colors, that we are drawn to what food energies our bodies need. "The color of food is key to the energy pattern of food and how its bimolecular nutrients will be bonded to specific cells and tissues in our bodies." Having awareness of the color of the foods we eat will lead us to consume the best foods for energy building in our bodies. More than two thousand years ago there was certainly much hidden wisdom in Hippocrates' admonishment: "Let food be thy medicine and medicine be thy food." It is said that in addition to this, he practiced his healing in rooms painted in soothing colors to assist in his treatments.
A diagram of the electromagnetic spectrum, showing various properties across the range of frequencies and wavelengths. Source: Wikipedia.com
Besides the use of color remedies in feng shui, color breathing can also enhance the healing process as well as maintain healthy balance in our bodies. Color breathing is one of the many qigong (chi kung) forms devised by the Chinese over thousands of years. Through the use of color breathing into the organs of the body, each organ benefits as well as all the functions that relate to the organ. The intent of this qigong practice is to absorb colors from nature into the organs that relate to them; from there the healing colored qi will spread throughout the entire body. It is a maxim that where the mind goes the qi follows, so a disciplined intention is necessary in this daily practice. One puts attention into the appropriate organ, then either visualizes the color of the organ from the Five Element Theory, or looks at the appropriate color in one's surroundings either in nature or in one's home or work environment that has been color balanced according to feng shui. Next, one visualizes inhaling that color into the appropriate organ. Liver is first and its color is green. Your intention fills the organ with the frequency of green nourishing energy, and as you exhale, this cleans out any toxic energy that has accumulated. This also helps ease any emotion of anger since this is the emotion associated with this organ. The green frequency qi will follow the meridian pathways and carry the healing energy throughout the body. The process is repeated with the other yin organs: spleen/yellow, heart/red, lungs/white, kidneys/blue. If you are unfamiliar with qigong, you may be skeptical about breathing in a color frequency. You need to suspend your judgment and keep an open mind. The proof is in the actual practice.
"Chi" is the Wade-Giles spelling; "Qi" is the Pinyin spelling. It is pronounced
chee⁴. with a falling tone.
There was a secret book written by Daoists two thousand years ago in China that dealt with the healing qi that came from trees. One of the cures it discussed involved the correlation between the color of a tree and human organs. It stated that matching a certain color tree to the relevant organ could ensure a healing for that organ. For example, the Chinese red apple tree affects the human heart. The white poplar affects the lungs and so forth.
Remembering the Qi of Heaven mentioned above, we have from the ancient scriptures of India:
"The body of the Lord the Creator of the Universe which is the same as the Universe itself, is composed of cosmic colors." …. The cosmic colors are at the root of everything tangible…We are continuously receiving from the cosmos our share of the seven cosmic colors which are nourishing our body…disease with its painful symptoms is nothing but the cry of the individual for the right cosmic color which is deficient. Disease may therefore be taken as nothing but the hunger for cosmic color. When that color hunger is satisfied by the supply of true colour disease disappears. The deficient color required by the individual can be supplied in many ways. Dr. R.B. Bhattacharyya. Magnet Dowsing Or the Magnet Study of Life.
^ Anna Cocilovo. "New Developments in Color Therapy." www.photonstimulator.com