What Color Is Your Aura? Psychics vs. Physics

No self-respecting psychic would end a session without reading your aura. They will inform you that your body radiates energy in colors that are unique to your personality (Fig. 1). For example, a blue aura signifies that you are reflective and calm. In contrast, a red aura indicates that you are fiery and assertive. The colors will vary from one psychic to another, but this discrepancy will be attributed to your mood swings caused by the pressures of modern life.

If you're not happy with their choice, they will let you pick one of your own. After all, why settle for one color when a rainbow has loads? Yet, if you ask about the link between energy and colors, they will veer into the murky waters of chakras and higher dimensions, and you will leave none the wiser. So, what kind of energy do our bodies really emit? And how does that energy relate to colors?

Fig. 1   Aura imitation. Credit: Radiant Human, Art photography by Christina Lonsdale.

Our bodies generate and exchange energy in various forms, but light is the only type we can see. Light is electromagnetic radiation that travels as waves, carrying energy. Besides visible light, which we perceive as colors, the electromagnetic spectrum includes six invisible bands: radio waves, microwaves, infrared, ultraviolet, X-rays, and gamma rays (Fig. 2).

These bands are defined by wavelength. As you move from radio waves toward gamma rays, wavelengths get shorter, and the radiation becomes more energetic. Visible light follows the same pattern: red sits at the lower-energy end, while blue is at the higher-energy end. However, wavelengths are not something we can easily visualize. So instead, we can associate the color a body emits with a more familiar concept: temperature.

Fig. 2   Full electromagnetic spectrum, from radio waves to gamma rays. Source: BBC Bitesize

According to Wien's displacement law, there is a strong correlation between an object's temperature and the radiation it emits. For instance, to glow blue, an object must be extremely hot, close to 18,000°F (10,000°C). This is the temperature of Sirius, the brightest star in the night sky (Fig. 3). As the temperature decreases, the emitted radiation shifts toward the red end of the visible spectrum, moving through yellow and orange hues. An example of this is the red supergiant Betelgeuse, which at 5800°F (3200°C) is much cooler than Sirius.

Fig. 3 Blue Sirius and red Betelgeuse. Credit: Hubble European Space Agency,

As an object cools further, its red glow weakens and eventually disappears from human sight. Fresh lava may glow bright orange, then deepen to red as it flows down the volcano and loses heat. At the edges of the flow, where cooling is fastest, the glow breaks into faint streaks and sparks before fading into darkness (Fig. 4). With further cooling, the lava's peak emission shifts into the infrared. It still gives off substantial thermal energy, making it far too hot to walk on, but its visible glow vanishes entirely.

Fig. 4 Eruption of Arenal Volcano, Costa Rica in 2006. Photo by Matthew.landry (Wikimedia Commons, CC BY-SA 3.0).

At 100°F (37°C), our bodies emit thermal radiation invisible to the human eye. This radiation can be detected by infrared cameras and by certain animals with specialized organs. Pit vipers, for example, have heat-sensitive pits between their eyes and nostrils (Fig. 5). These pits contain membranes that sense infrared radiation from warm-blooded prey. Viper's brain converts this information into images. It is unclear whether images are in color. But even if they are, these colors must be different from those they can see with their eyes, because their brain has already mapped them onto the visible spectrum.

Fig. 5 Salazar's pit viper. Photo courtesy of Zeeshan A. Mirza

You might argue that roses are red and violets are blue without being heated to the temperature of stars. That's true, but flowers don't own their colors; they borrow them from the Sun. At about 10,000°F (5,500°C), the Sun emits light across the visible spectrum, which our eyes perceive as white. Roses appear red because their petals reflect red wavelengths while absorbing the others. Similarly, iolets appear blue because their pigments reflect those wavelengths into our eyes. When the Sun sets, it takes those colors with it, which is why flowers fade into grey at night, while lava can glow red. One shines with its own light, while others merely reflect someone else’s.

Colors evoke emotions, making it natural for us to use them to express our feelings. However, when we say we're "seeing red" or "feeling blue," it's not meant literally. The colors that psychics describe as human auras are imaginative creations. Science doesn't concern itself with imagery, leaving that to poetry. If we want to believe that humans are as beautiful as rainbows, we don't need a psychic's validation. We assess beauty through good deeds, not wavelengths.