Light is fundamental. Our bodies are biological light-receptors that transform sunlight into life-sustaining energy.

A photon is, most simply, a "particle of light." Although light spreads as an electromagnetic wave, it can be created or absorbed only in discrete amounts of energy, known as photons. The energy of a photon is greater the shorter the wavelength. The energy is smallest for the photons that comprise radio waves, increasingly larger for microwaves, infra-red radiation, visible light, and ultra-violet light. The photons of x-rays, gamma rays, and cosmic rays have the shortest wavelengths and greatest energy (the "highest vibration").

Living cells emit weak electromagnetic radiation. Your skin emits about 30 photons per square centimeter per second. While not visible to the human eye, you emit light. You glow! But not enough to get arrogant. The scientific term is "ultra-weak bioluminescence."

Objects absorb specific frequencies of white light. The color of an object is actually the part of the spectrum the object cannot absorb. This is reflected and experienced as its color.

Our eyes can recognize several million variations of hue (exact location on the spectrum).

Light energy has two fundamental dimensions: intensity & wavelength.

• Intensity is the number of photons that fall on a given area—determines brightness
• Wavelength is literally the length of the wave
  • A radio wave has a relatively long wavelength (thus its photons have less energy)
  • Visible light is in the middle of the spectrum
  • Infrared is just below visible light in its energy (longer wavelength)
  • Ultraviolet just above visible light in its energy (shorter wavelength)
  • X-rays, gamma rays, and cosmic rays have progressively higher energy (shortest lengths)

The human energy field is composed of subtle energies that sensitive people often see as color.

The vibrations of the human energy field are as much as a thousand times higher than the vibrations of the bioelectrical signals of the nerves and muscles, which is why it is not usually visible to the naked eye. This finding has caused some scientists to speculate that in addition to the well-established place of color on the electromagnetic spectrum, color may also be a quality of subtle energy that is not on the electromagnetic spectrum at all (like subtle energy perhaps), yet one that still objectively exists in the physical universe.

Meridian Colors: While Donna’s students have heard her repeatedly say, "Your energies are as unique as your thumbprint," and have heard her emphasize that the chakras don’t have fixed colors like some books contend, the meridians do reflect a fixed color scheme. This is because each organ in the body has a vibratory rate. Your stomach’s energy is different from the energy of your liver, but it is similar to the energy of your friend’s stomach. Where the chakras and the aura reflect the unique differences of people, the meridians reflect our commonalities – our organs – not our uniqueness. A meridian’s color may differ from one person to the next in tone, shade, and intensity, depending on the health of the meridian and the related organs, but there is enough uniformity that it is possible to develop a systematic treatment approach, such as the one conveyed on the "Balancing the Energies Using Color Gels" chart.