Raw sienna is a versatile and warm earth tone, often used in watercolour painting to create natural, subdued colours. When mixed with other colours, it can produce a wide range of hues, from soft, muted tones to rich, vibrant ones. It can tone down bright hues, add warmth to cool colours, or create a broad spectrum of natural greens, oranges, browns, and neutrals. In this article we will discover the origins of Raw Sienna and I will share with you some colour mixes to try at home.

Extracted from the earth

The term ‘earth colour’ is given to naturally occurring colours that come from the earth, for example iron oxides from clay. They include Yellow Ochre, Raw Sienna, Burnt Sienna, Raw Umber, Burnt Umber and Terre Verte. Sienna is an earth colour and is made up of iron oxide and manganese minerals. Depending on its chemical composition, it can come in various hues ranging from a yellow-brown to a red-orange. Unlike Yellow Ochre, which is generally opaque, Sienna is more transparent. When heated, it becomes a reddish brown and is called Burnt Sienna.

Prehistoric origins

Like other earth colours, Sienna was one of the first pigments used for painting and is found in prehistoric cave art dating back 40,000 years. Examples remain bright to this day, showcasing the durability of Sienna. Though the term sienna was first recorded in English as recently as 1760, the name of the pigment derives from ‘terra di Siena’, which means ‘Siena earth’, referring to the city of Siena in Tuscany where it was produced. Mineralogist Alessandro Fei described the clays of this region as ‘colouring earths’. Extraction of earth pigments in Tuscany have been occurring since antiquity, but the first documented records date back to the early 18^th century, and it became a flourishing economy in the 19^th century all the way through to World War II. There are many extraction sites across Tuscany, including the slopes of extinct volcano Monte Amiata.

Raw sienna is a highly versatile color

Prized for it’s versatility Raw Sienna is a staple in many an artists palette for a number of reasons;

Creating natural earth tones – Raw Sienna’s warm yellow-brown hue is ideal for depicting soil, sand, rocks, and other earth-based elements in landscapes.

Skin tones – its soft, warm undertone makes Raw Sienna useful for painting skin tones. Mixed with reds, browns, or whites, it creates a range of natural flesh colours, particularly for warmer, sun-kissed complexions.

Warm underpainting & glazing – in watercolour, Raw Sienna is often used as a warm base colour or underpainting. It provides a glowing warmth that can enhance the overall colour harmony of a painting when layered with other hues. It’s especially useful for creating depth in backgrounds or foundation layers. Raw Sienna is semi-transparent which makes it ideal for layering over other colours to warm them up without overpowering.

Depicting sunlight – Raw Sienna is ideal for capturing the warm glow of sunlight, particularly in morning or evening scenes. It works well for creating the effect of golden light in skies, fields, and reflections on water.

Foliage – it’s frequently used to depict autumn foliage, dry grasses, and sunlit areas of vegetation. When mixed with greens and browns it can create the look of natural, sunlit leaves or trees in transition during autumn.

Aging & patina effects – Raw Sienna is great for conveying the look of aging in buildings, stones, or other natural materials. It mimics the subtle warm tones of weathered wood, aged stone, and rust.

Neutralising cool colours – Raw Sienna is useful for neutralizing cooler colours like blues and greens. It can create more balanced, harmonious colour schemes when combined with cooler hues, particularly in landscapes.

Subtle shadows – When diluted, raw sienna produces gentle, warm shadows, making it suitable for soft shadow areas in portraits and landscapes. It can help suggest the warmth of reflected light in shadowed areas without being too harsh or dark.

Colour Mixing with Raw Sienna

It is clear that used on it’s own Raw Sienna is particularly valuable for painters looking to create natural, warm, and earthy effects, whether in landscapes, portraits, or still life’s. Lets take a look at how Raw Sienna can create a myriad of hues by mixing it with other colours in your palette.

I have created a series of swatches below. Raw Sienna is painted out at 100% Raw Sienna on the left hand box and the other colour being mixed is swatched on the right hand box again at 100%. The two smaller boxes below these illustrate how the pigment behaves with more water added to the wash. I have then started to add another colour to the Raw Sienna wash. The three boxes in the middle show the graduation from Raw Sienna as more and more of the other colour is added to the wash.

1. Raw Sienna + French Ultramarine

• Result: Muted blues, greens and neutrals.
• Use: Great for landscapes, especially for distant hills, foliage, and shadows. The resulting green is more natural and earthy. Great for creating texture in your work too as both colours are granulating.

2. Raw Sienna + Cobalt Blue

• Result: Soft olive greens and browns and muted blues.
• Use: Good for skies, distant foliage, and light shadows.

3. Raw Sienna + Winsor Blue (red shade)

• Result: Vibrant, earthy greens and deep sea greens.
• Use: I absolutely love this colour mix. Useful for vibrant foliage, especially in sunny or tropical settings and seascapes. Check out the texture! As you can see from the second box on the right it’s great for neutralising the vibrant Winsor Blue. I’ve just dropped in a small amount of Raw Sienna into my Winsor Blue to create this useful blue shade.

Comparison of blues mixed with Raw Sienna

The three different blues used to make mixes with Raw Sienna create a wide variety of muted blues, greens and browns. Use French Ultramarine or Cobalt Blue if you are wanting to add extra texture to your work as the two colours create a supergranulating effect when mixed with Raw Sienna. Winsor Blue (red shade) is a staining colour and makes for great foliage effects, created by lifting out with a damp brush once the wash is dry.

4. Raw Sienna + Burnt Sienna

• Result: Rich, warm browns and oranges.
• Use: Perfect for autumn scenes, skin tones, and warm earthy textures.

5. Raw Sienna + Raw Umber

• Result: Muted, cool browns.
• Use: Cooler mixes than Burnt Sienna. These are good for creating shadows and wood textures.

6. Raw Sienna + Alizarin Crimson

• Result: Warm, reddish-browns and terracotta shades.
• Use: Good for brick, earthy tones in landscapes, and warm highlights in portraits.

7. Raw Sienna + Cadmium Red

• Result: Warm, fiery oranges and reds.
• Use: More vibrant than Alizarin Crimson. Great for sunsets, fiery skies, and adding warmth to your painting. Cadmium Red is an opaque pigment which is important to note if you are using on top of other washes.

8. Raw Sienna + Payne’s Gray

• Use: This is one of my favourite combinations. Ideal for creating atmospheric skies, distant mountains, and subdued shadows.
• Result: Soft, cool greys and neutrals.

9. Raw Sienna + Titanium White

• Result: Soft, creamy yellows and off-whites.
• Use: Useful for highlights, light skin tones, and warm, subtle gradients. When mixed with more white than Raw Sienna it closely resembles Buff Titanium. When the mix has a higher proportion of Raw Sienna it makes a good alternative to Naples Yellow.

10. Raw Sienna + Viridian

• Result: Muted, olive and sap greens.
• Use: Ideal for more subdued foliage and natural, earthy tones in landscapes.

In summary

The mixes above can be adjusted depending on your desired outcome. You can see from the swatches above that varying the amount of water in your mix creates a range of tones, from light washes to deeper, more intense colours. Always test your mixes on a scrap of watercolour paper to see how they behave once dry, as watercolours often change slightly in colour. It’s handy to keep a note of colour mixes you find useful as a reference for future paintings. So over to you now, I hope you enjoy experimenting with these combinations or finding your own colour mix with Raw Sienna – let us know if you find a new exciting combination!