
Raw Sienna is one of the traditional earth tones made from PBr7. It’s an earth yellow-orange, more yellow than Burnt Sienna but typically more orange than Yellow Ochre (PY42).
Comparison to Other Colors
Da Vinci – Raw Sienna Deep (PY42)

This isn’t actually Raw Sienna – it’s a yellow ochre pigment (PY42 or synthetic yellow oxide). This is not particularly “deeper” than Raw Sienna, but I think they were trying to match the naming convention they’d established by calling their PR101 transparent red oxide “Burnt Sienna Deep.” Like other yellow ochres, this is more yellow than Raw Sienna. This color is also more granulating than Raw Sienna. It is comparable to MANS (discussed next), though I find it a bit weak and sticky (binder-heavy), and not as pleasant to paint out.
Monte Amiata Natural Sienna (PBr7)

Monte Amiata Natural Sienna is made from the same pigment as Raw Sienna, but it is yellower than the typical Raw Sienna, closer in hue to a typical Yellow Ochre. It’s also granulating.
Burnt Sienna Deep (PR101)
Raw Sienna is more yellowy than Burnt Sienna variants.

Comparison to Other Brands
Daniel Smith – Raw Sienna
Here’s a comparison from dot cards of Daniel Smith earth colors. Daniel Smith’s Raw Sienna is more orangey, less pigmented, and more granulating than DV’s.

Color Mixes
Burnt Sienna Deep (PR101)

With DV’s answer to Transparent Red Oxide, Burnt Sienna Deep, Raw Sienna can mix a range of earthy yet glowing oranges.
Indian Red

Backing your way into Burnt Sienna hues! The light values make peach colors that might be good for portraits of people with light skin tones.
Perylene Violet (PV29)

Color-separated muted warm browns. Not my favorite mix.
Dioxazine Violet

Makes brown, I guess. Not really a fan.
Smalt

Like MANS, Raw Sienna makes pretty neutral grays with WN Smalt (PV15).
Indanthrone Blue (PB60)

The orangey tones of Raw Sienna effectively mute Indanthrone Blue to a Payne’s Gray type color; with more RS, it moves into a tan/gray.
Ultramarine Blue (PB29)

Very nice mixes with Da Vinci’s Ultramarine Blue (PB29), a middle ultramarine; I like how a little bit of RS turns it into a dark muted blue, a moderate amount grays it, and a mostly-RS mix is a very nice Yellow Ochre hue. The second-to-last is pretty ugly. There is some color separation in all these mixes.
Cobalt Blue (PB28)

Similar to the UB mixes, but subtly more greenish all around.
Payne’s Gray

With actual Payne’s Gray the color mix is even more muted. The diluted, mostly RS mix has a dead-grass look to me. But it’s a bit muddy.
Indigo

RS mutes Indigo to gray. Both colors have a yellow cast, so there’s a muddy greenness to these mixes. The diluted mostly-RS mix has a very smooth look that to me resembles kraft paper.
Cerulean (PB35)

Greenish-gray muted colors, which remain color-separated.
Phthalo Turquoise (PB16)

Finally some mixes that go green. You have to start with a pretty greenish mixing color to begin with.
Phthalo Green Blue Shade (PG7)

A nice range of bright yet naturalistic greens similar to those with a yellow-orange (e.g. PY65).
Chromium Oxide Green (PG17)

A classic desert foliage mix, resulting in green-tans.
What Others Say
This is my ‘banker.’ It’s very versatile and I use it on every painting, beginning each sky with it. It’s an ‘earth’ colour – one of the oldest colours known. I much prefer it to yellow ochre, as it’s much more transparent.
Ron Ranson, On Skies (1996)
The color of raw sienna resembles dried meadow grass, pale fresh cut woods such as maple or pine, and weathered plaster. I believe the Winsor & Newton formulation is closest to the historical color, which is slightly lighter valued, less saturated, cooler (more yellow), and much more transparent than yellow ochre; the differences between raw sienna and yellow ochre become less pronounced in tints, though raw sienna usually shifts farther toward a bright yellow.
Bruce MacEvoy, handprint.com
A beautiful neutral orange-yellow. In my explorations, the Daniel Smith version is the most lovely. Many others are more like a yellow ochre. Another option is Quinacridone Gold or Quinacridone Gold Deep. One of the special qualities of Raw Sienna is that it doesn’t really make greens when mixed with a blue so can be gorgeous in a sky as the warm yellow glaze above the horizon, with the blue above and no green!
Jane Blundell, Earth Colours
Raw Sienna is the perfect pick for dry grasses, distant winter leaves, parts of a tree branch, and the lightly tinted feathers of a Song Sparrow.
Scratchmade Journal, Comparing & Mixing Earth Tone Yellows
My Overall Review of Raw Sienna
My toxic trait is that I underestimate earth tones. I found Raw Sienna boring when I first tried it, but it’s grown a lot in my estimation!
In the Desert
I found it especially useful in painting the Mojave Desert, where its caramel-orange tones matched the landscape better than the yellower hue of Yellow Ochre or Monte Amiata Natural Sienna.

Many people cite Buff Titanium (PW6:1) as a base for sand, light-colored stone, and the buff tones in birds’ feathers, but I find I prefer diluted/light value Raw Sienna for all of those things. Less opaque than Buff, it has more luminosity and gives you more options for deepening the color. When I find Raw Sienna too orange, a bit of Cerulean brings it into more of a gray-brown space.

Winter in the Northeast
Living in a totally different biome, a deciduous forest, it took me awhile to figure out how to use Raw Sienna locally. For tree trunks I use earth orange and blue to get a cool brown that’s borderline warm gray. For things like fields of wheat or dry grass, I typically use MANS or Yellow Ochre. Then, when building the Winter Palette, I discovered that Raw Sienna is actually better for those grasses! Although yellower earths are closer to the right color, they’re harder to mute and darker – I could use a neutral darkener like Neutral Tint or black, or add to a mixed gray like the ones I make from TRO + UB, but it’s always a bit fussy. I found myself thinking “if only Yellow Ochre was a bit more orange, I could neutralize it with blue.” Then I realized that is Raw Sienna!

Muted down with blue, it’s the perfect muted caramel/beige color for dry grass, which is so prevalent in winter.
It’s also a great mixer for cloud grays, also seen in the example above, when used as the yellow in a primary triad. It never comes through too strongly in a mix, like bold yellows can, but provides that nice warm dimension to a gray.
Monte Amiata Natural Sienna has been my diehard earth yellow for the last couple of years, but I think now it’s time for Raw Sienna to take over!
On my palette? Yes!
Favorite version: Da Vinci
I rarely obsess about raw sienna, but it’s one of the colors I seem to just eat up in my palettes. I guess I use it in dusty roads and fields of grain and burnt-out grasses, which are everywhere I go in Europe by the late summer. And some green-based green mixes.
I find many of the different versions kind of interchangeable for those use-cases though, since I am adjusting it anyway. Now, what I really need to figure out is which versions won’t put green in my skies, because some CLEARLY will.
Oh, and I really like the modeling on the left mountain, but I agree that Buff Titanium tends to take away from the glowy look of watercolor.
I though Raw Sienna was traditionally PBr7, but I’ve noticed a lot (maybe most?) available options are PY42 or PY43 based, or a mix, so they definitely go green. I really prefer the PBr7. I feel like being able to gray it with blue is the whole point. The range of beiges is not exciting but very useful.
Something else to maybe add to this post after I try it more: I’m reading “Ron Ranson On Skies” and he starts nearly every sky painting with a light wash of Raw Sienna. It creates a subtle warm glow where it peeks through.