Burnt sienna is an earth pigment that has long been used in art and design. It is made from naturally occurring iron oxide-rich clay deposits that are heated at high temperatures, changing the clay’s color from yellow-brown to a rich, reddish-brown. But is burnt sienna considered a red or a yellow? The answer lies in examining burnt sienna’s unique properties and origins. As we’ll explore, while burnt sienna sits somewhere between red and yellow, it is generally categorized as a reddish-brown due to its higher proportion of red undertones. Understanding where burnt sienna falls on the color spectrum helps artists use it most effectively in their works.
The Origins and Composition of Burnt Sienna
To understand burnt sienna’s place between red and yellow, it helps to look at where it comes from and what it’s made of. Burnt sienna originated as a traditional pigment made by heating yellow-brown raw sienna clay found in areas like Siena, Italy. The iron oxide content in the clay gives raw sienna its characteristic yellow-brown color. When this clay is heated at high temperatures through a process called calcination, it turns a much deeper red-brown. The high heat removes water from the clay and changes the molecular structure of the iron oxide, altering the way the material absorbs and reflects light. This transforms the raw sienna into the richer, redder burnt sienna pigment.
The main ingredient giving burnt sienna its color is iron oxide, specifically hydrated iron oxide (Fe2O3·H2O) in raw sienna which converts to anhydrous iron oxide (Fe2O3) in burnt sienna. Iron oxide comes in several forms which produce different colors depending on the specific molecular structure. The form of iron oxide in burnt sienna is hematite, which tends to produce redder hues than other forms like goethite (yellow) or magnetite (black). So while burnt sienna still retains some of the yellow undertones of raw sienna, the hematite iron oxide shifts the balance further toward red.
Where Burnt Sienna Falls on the Color Wheel
Looking at the color wheel helps provide a visual depiction of burnt sienna’s relationship to red and yellow. On a typical RYB (red, yellow, blue) color wheel, burnt sienna would be positioned between the yellow and red sections, leaning closer to red. It sits next to other reddish-browns like rust or cinnamon. While burnt sienna contains both red and yellow undertones, the red dominates due to the higher proportion of hematite iron oxide. Burnt sienna is considered a tertiary color, meaning it is made by combining the primary colors red and yellow. This combining gives burnt sienna an orangey undertone. But the character of burnt sienna is decidedly more red than orange due to the heat-induced changes to the raw sienna clay’s molecular structure during calcination. So on the color wheel, burnt sienna falls much closer to the red family than the yellow/orange family.
The Undertones and Color Mixing Properties of Burnt Sienna
Examining burnt sienna’s undertones and how it mixes with other colors also sheds light on whether it sits more in the red or yellow color camp. While burnt sienna contains both red and yellow undertones, artists describe the red undertones as being more dominant. The yellow undertone is more subtle and acts like a “warming” modifier to tone down the redness. Some describe burnt sienna as having orange, brown, or golden undertones in addition to the red and yellow. But the overall effect is a color heavily weighted toward red.
This becomes especially apparent when burnt sienna is mixed with other colors. Mixing burnt sienna with blues will subdue the blue, making it more earthy and brown. Mixing it with reds will bolster and enhance the reds. Mixing burnt sienna with yellows will deepen and mute the yellow, shifting it toward orange and brown. So in mixing burnt sienna generally functions more as a reddening agent than a yellowing or lightening agent. This indicates burnt sienna is predominantly red despite retaining some yellowness from its raw sienna origins.
| Color 1 | Color 2 | Result |
|---|---|---|
| Burnt Sienna | Blue | Muted blue with earthy brown tones |
| Burnt Sienna | Red | Deeper, enriched red |
| Burnt Sienna | Yellow | Darker orange-brown |
The Use of Burnt Sienna in Art
Looking at how burnt sienna has historically been used in art also supports it being categorized primarily as a red versus a yellow. Burnt sienna emerged as an important pigment in the Renaissance era, valued for the rich reddish glazes it produced in oil painting. The pigment lent a transparent, golden tone to flesh and drapery in Baroque portraiture and was mixed with blues to create deep greens in landscape paintings.
In modern art, burnt sienna continues to be used mainly for its warm, earthy red properties. It is popular for creating a rusty red color for painting brick, stone, clay, wood, and autumn foliage. Mixing burnt sienna with ultramarine makes a muted violet-gray. Combining it with phthalo blue creates an earthy green. So burnt sienna most often functions as reddish tone that subdues brighter blues, yellows, and greens. This demonstrates how burnt sienna sits squarely as a red on the artistic color spectrum.
Technical Classifications of Burnt Sienna’s Color
Looking at the technical specifications of burnt sienna’s color also confirms its categorization as a red-brown rather than a yellow-brown. In color documentation like Pantone, burnt sienna fits under reds rather than yellows. For example:
– In Pantone Textile Paper eXtended (TPX), burnt sienna is categorized as a red, with the code 19-1522 TPX.
– On web colors, burnt sienna’s hex code #E97451 places it with other shades of red-brown.
– In computer color picking it sits with reds, at RGB (233,116,81).
So in technical color documentation, burnt sienna consistently falls under red or red-brown rather than yellow or orange.
Conclusion
While burnt sienna retains some of the yellow tones of its raw sienna origins, it sits predominantly in the red color family. The heating process used to create burnt sienna converts the iron oxide in raw sienna clay to a form that absorbs and reflects more red light. On the color wheel, burnt sienna falls much closer to red than yellow. Its undertones are more red and orange than yellow, and it generally mixes to enhance reds rather than yellows. Historically burnt sienna has been valued more for its warm, earthy red properties than any yellowness. And color documentation like Pantone consistently classifies it as a red or red-brown. So although burnt sienna straddles the line between red and yellow, it sits firmly on the red side, making it accurate to describe it as a reddish-brown versus a yellowish-brown. Understanding where burnt sienna fits on the color spectrum helps artists best leverage its unique color qualities.
