Brown is a color that is ubiquitous in nature, from tree trunks to dirt to animal fur. But is brown actually considered a “real” color in the scientific community? This article will examine the physics and perception behind brown, and look at whether it qualifies as its own distinct color according to scientific definitions.
The Physics of Brown
To understand if brown is a real color scientifically, we first need to consider how color is created physically. The color we perceive an object to be is based on which wavelengths of visible light are absorbed and which are reflected. The visible light spectrum ranges from violet and blue light with short wavelengths, to green and yellow light with medium wavelengths, and orange and red light with longer wavelengths.
When an object appears brown, it means the surface is absorbing more of the shorter blue wavelengths, and reflecting more of the longer orange and red wavelengths. But brown objects reflect a wide range of wavelengths across the spectrum. This gives brown a very broad range of hues, from reddish browns to yellowish browns.
This means brown is not associated with a single wavelength or narrow band of wavelengths like other colors are. There is no “brown wavelength” of light. So based on the physics alone, brown is not considered a spectral color like red, green or blue.
The Perception of Brown
Another way to examine if brown is a real color is to look at how the human brain perceives it. Our eyes have receptors called cone cells that detect different wavelengths of light. We have cone cells that are specialized to see red, green and blue specifically. All the colors we see are constructed by our brain based on signals from these three types of cones.
When our eyes see a brown object, the brown color is created in our mind by a combination of the red and green cone cells being stimulated. There is no “brown receptor” that detects brown light exclusively. This means brown is not perceived as a primary color by the human visual system.
| Cone Cell Type | Color Detected |
|---|---|
| S-cones (short wavelength) | Blue |
| M-cones (medium wavelength) | Green |
| L-cones (long wavelength) | Red |
Based on the physiology of color vision, brown is a secondary color rather than a primary color that our eyes can sense directly. This provides more evidence that brown may not technically be a distinct color in scientific terms.
Color Theory
Looking at traditional color theory also gives clues into the scientific status of brown. In art and design, the primary colors are considered to be red, yellow and blue. All other colors can be created by mixing primary colors together.
Brown is made by mixing complementary colors from opposite sides of the color wheel, such as red and green, or orange and blue. This reinforces the idea that brown is seen as a secondary color rather than a primary color with a unique color wavelength.
| Color 1 | Color 2 | Mixed Color |
|---|---|---|
| Red | Green | Brown |
| Orange | Blue | Brown |
| Yellow | Purple | Brown |
However, some more modern color theories consider brown to be a tertiary color made by combining the primary and secondary colors together. For example, browns can contain hints of orange (made from red and yellow) and green (made from yellow and blue). So this provides some evidence that brown has enough of a unique identity to be considered its own color category.
Color Spaces
Looking at how colors are classified and organized in color space models also gives insight into the scientific status of brown. The RGB color model is based on the primary colors red, green and blue. The CMYK model is based on the primaries cyan, magenta, yellow and black. Brown is not explicitly included as a color in these widely used models.
However, some more advanced color models like LAB and Munsell make room for brown shades. These spaces define colors based on human perception, placing browns along the spectrum from yellows to darker tints.
Computer display colors are defined by RGB values on a scale from 0 to 255. While there is no single brown value, various shades of brown can be created by combining RBG values. For example:
| Brown Variation | RGB Values |
|---|---|
| Light Brown | 207, 185, 151 |
| Medium Brown | 152, 118, 84 |
| Dark Brown | 101, 67, 33 |
The fact that browns can be defined by RGB combinations implies they may have enough of a distinct identity to be labeled as a separate color in some contexts.
Pigment vs. Light
Another factor to consider is the difference between color as pigment vs. color as light. As a pigment or dye, brown has a very concrete identity. There are specific brown pigments such as raw umber or burnt sienna. This contrasts with brown light, which does not have its own narrow wavelength band.
So while brown may not technically qualify as a spectral color of pure light, it likely qualifies as a distinct color category when it comes to pigments and dyes. There are clear variations between light browns, medium browns and dark browns when defining them as a pigment.
Conclusion
While brown is generally not considered a primary color with its own wavelength, or a color that human eyes can sense directly, there is some debate around whether it still qualifies as a unique color in scientific terms. Arguments can be made both for and against brown having enough of a distinct identity scientifically to be labeled as its own color category.
Overall, the evidence suggests brown occupies an in-between status scientifically. Strictly speaking, it is a secondary color created by combinations of primary wavelengths. But brown also has enough distinguishing characteristics in terms of hue, shade and pigmentation to potentially qualify as its own tertiary color group. Most color scientists and theorists agree that brown exists as a color in people’s minds and perceptions, even if it is not a pure spectral color.
So in summary, while brown may not be a primary or spectral color, it likely has enough of a unique identity scientifically to still be considered its own real color category, at least in certain color models and definitions of color. The ubiquity of brown in the natural world also gives it a concrete existence as a color, even if it doesn’t map neatly onto the physics or perception of pure primary colors.