The Colors of Light Therapy: Uses and BenefitsLast Updated:
Chromotherapy  is an alternative treatment method that utilizes electromagnetic radiation in various colors. The spectrum consists of visible and invisible light wavelengths delineated by color. Chromotherapy refers mainly to the therapeutic use of visible light.
Chromotherapy theorizes that different wavelengths of light possess different therapeutic properties. Scientific research supports this assertion, proving that different light colors provide different health, wellness, and appearance benefits.
Table of Contents
Understanding the Electromagnetic Spectrum
Wavelengths are measured in nanometers (nm), equal to one-billionth of a meter. Light wavelengths measure approximately as follows:
- Ultraviolet (UV): 10 to 380 nm
- Violet — 380 to 450 nm
- Indigo — 440 to 460 nm
- Blue — 450 to 495 nm
- Cyan — 485 to 510
- Green — 495 to 570 nm
- Yellow — 570 to 590 nm
- Amber — 580 to 600 nm
- Orange — 590 to 610 nm
- Red Light-Emitting Diode (LED) — 610 to 700 nm
- Near-Infrared (NIR) — 700 to 900 nm
- Infrared — 900 to 1400 nm
Certain color ranges overlap; for instance, blue, cyan, and green. When you view a rainbow, there are no “lines” between the colors; rather, they blend together. For this reason, wavelength ranges are approximate, not precise.
The spectrum is continuous like a circle, meaning that the low end blends with the high end. This is why pink light is not noted on the spectrum. The appearance of pink light is created by the shortest visible waves (violet) combining with the highest visible waves (red and some NIR).
Also notably missing from the measurable light spectrum is white light. This is because white light is a combination of all the visible light on the spectrum and does not have its own wavelength measurement.
Light ranging from approximately 380 to 800 nm is visible to the human eye. The sun’s UV rays are invisible. When we visualize sunlight, we only see the violet rays, not the UV rays. On the high end of the spectrum, light becomes invisible somewhere within the NIR range.
Colors of Light Therapy and Their Benefits
Light wavelengths penetrate your skin and into your body. While generally the longer the wavelength, the deeper the penetration. However after peaking at 750 nms, the penetration power of longer wavelengths goes down a little bit (as shown in the figure below). The depth of penetration determines the biological effects light therapy can stimulate.
Now let’s explore the different colors of light therapy and their treatment advantages.
White Light Therapy
Sunlight is a necessary source of natural Vitamin D and it boosts your body’s production of serotonin. A lack of natural sunlight can cause listlessness, sleep problems, and certain forms of depression.
Bright white light is useful for replacing the natural sunlight that you may not get enough of due to today’s predominantly indoor lifestyle and during winter months when the days are shorter. White light can elevate your mood, boost your energy level, and help with concentration.
White light can treat sleep disorders and Seasonal Affective Disorder . White light can also help with jet lag and addictive behaviors such as alcohol abuse or compulsive eating.
Pink Light Therapy
Pink light can help eliminate blood impurities and may strengthen veins and arteries. Pink is one of the least common and least studied forms of light therapy.
Violet/Purple Light Therapy
Violet light only penetrates your body to the lower epidermis (outermost skin layer). It is a calming, cool color that reduces inflammation, increases skin cell generation, and kills bacteria. Violet light kills bacteria, making it a successful acne treatment [3.] It can relieve emotional exhaustion and elevate your mood.
There is evidence that violet light therapy can be useful in treating ocular conditions. One study  showed that violet light reduced myopia (near-sightedness) in mice.
Indigo and Blue Light Therapy
We encounter blue light every day via electronic devices and indoor lighting. Excessive blue light exposure can produce harmful side effects like headaches, sleep disturbances, and concentration problems.
Blue light, however, also possesses therapeutic properties when used safely.
Blue light penetrates your dermis (directly beneath the epidermis). Because bacteria located beneath your skin are the cause of most acne, blue light is effective for preventing and eliminating acne  and for treating acne scars. Blue light also treats skin conditions such as rosacea, eczema  , and psoriasis .
Blue light can help treat any condition with a root cause on or directly beneath your skin’s surface. Examples include:
- Cellulite reduction
- Decreased appearance of varicose veins and spider veins
- Healing of sun damage
- Superficial wound healing
Cyan Light Therapy
Cyan light penetrates midway through your dermis, slightly deeper than blue light. Cyan is an effective anti-inflammatory treatment and can successfully treat acne, reduce the appearance of swollen capillaries, soothe skin irritation, and provide surface pain relief.
Green Light Therapy
Green light penetrates your dermis, almost reaching the subcutaneous tissue below. Studies have shown that green light is effective for relieving pain.   Green light is also beneficial for treating similar skin conditions as blue light, especially with regard to skin tone and complexion. Sunspots, melasma, rosacea, eczema, and psoriasis can all benefit from green light.
Yellow, Amber, and Orange Light Therapy
These wavelengths penetrate the subcutaneous tissue beneath your dermis. Like green and blue light, they are effective at treating skin issues like eczema, sunburn, psoriasis, and creating an even skin tone. Yellow/amber/orange light therapy is one of the less common types; however, it can help flush waste from your skin, elevate the functioning of your lymphatic system, and stimulate cellular energy to some extent.
One study proved that 590 nm light therapy after laser skin treatments reduced the intensity and healing time of skin irritation. 
Red and NIR Light Therapy
Of all types of light therapy, red and NIR light provides the widest range of benefits. Because they penetrate your body more deeply than any other type of visible light, red and NIR wavelengths (especially when used in conjunction) activate your body’s innate healing powers and stimulate biological change at the cellular level. Read more about the best nm wavelength for red light therapy.
Red light stimulates the mitochondria of cells at all levels within your body, including brain cells inside your skull and cells within your bones. It even activates the production of new stem cells. Increased cellular energy allows your body to access its peak level of healing and rejuvenation, providing benefits including but not limited to:
- Weight Loss Assistance
- Anti-Aging 
- Pain Management 
- Better Athletic Performance 
- Improved Brain Health 
- Wound Healing 
UV and Infrared Light
UV sunlight is readily available without any device. As we know, however, the sun can have damaging effects that need to be mitigated. Skin and eyes need to be protected. Exposure to direct sunlight is beneficial; however, it must be absorbed carefully and in small doses.
Infrared light is not readily available in at-home light therapy devices because it presents too many health risks. Like UV rays, infrared rays are thermal (heat-producing) and capable of burning your skin and causing internal organ or DNA damage. Infrared therapy is generally limited to very serious conditions such as severe brain injury or degenerative diseases like Alzheimer’s and Parkinson’s diseases.
The most common at-home light therapy devices utilize primarily red and blue light. As we have discussed here, however, there are uses for other colors of light, and these devices are also available.
Used per the manufacturer’s recommendations, at-home color light therapy devices can provide significant healing, restoration, and rejuvenation. Light therapy can be administered conveniently in your own home and works in conjunction with other forms of therapy.
 A Critical Analysis of Chromotherapy and Its Scientific Evolution (opens in a new tab)
 Light therapy for preventing seasonal affective disorder (opens in a new tab)
 420 nm intense continuous light therapy for acne (opens in a new tab)
 Short-Wavelength (Violet) Light Protects Mice From Myopia Through Cone Signaling (opens in a new tab)
 Efficacy of blue light vs. red light in the treatment of psoriasis: a double-blind, randomized comparative study (opens in a new tab)
 Clinical efficacy of blue light full body irradiation as a treatment option for severe atopic dermatitis (opens in a new tab)
 Prospective, Randomized Study on the Efficacy and Safety of Local UV-Free Blue Light Treatment of Eczema (opens in a new tab)
 A Dynamic Model for Prediction of Psoriasis Management by Blue Light Irradiation (opens in a new tab)
 Long-lasting antinociceptive effects of green light in acute and chronic pain in rats (opens in a new tab)
 Exposure to green light may reduce pain (opens in a new tab)
 Improvement of post-fractional laser erythema with light-emitting diode photomodulation (opens in a new tab)
 A Controlled Trial to Determine the Efficacy of Red and Near-Infrared Light Treatment in Patient Satisfaction, Reduction of Fine Lines, Wrinkles, Skin Roughness, and Intradermal Collagen Density Increase (opens in a new tab)
 Low-Level Laser Therapy for Fibromyalgia: A Systematic Review and Meta-Analysis (opens in a new tab)
 Improvement of Performance and Reduction of Fatigue With LLLT in Competitive Cyclists (opens in a new tab)
 Shining light on the head: Photobiomodulation for brain disorders (opens in a new tab)
 Effects of LLLT on wound healing (opens in a new tab)