Winsor & Newton Cobalt Blue Watercolor Review: An Essential Blue
Winsor & Newton Cobalt Blue is one of the foundational colors on my watercolor palette. This classic blue is low staining, easy to lift, and incredibly versatile for skies, water, shadows, and color mixing. It’s also expensive—but Cobalt Blue is one of those pigments I consider worth the price.
In this watercolor review, I’ll look at how Winsor & Newton Cobalt Blue behaves on paper, including washes, lifting, color mixing, and its overall usefulness on a watercolor palette.
Watercolor Essentials: Cobalt Blue (PB28)
Cobalt Blue (PB28) is generally considered one of the purest blue pigments you can put on a watercolor palette. It sits in that sweet spot between a yellow-leaning blue and a red-leaning blue, which makes it incredibly useful for mixing.
If I were building a palette from scratch, this would be one of the very first colors I would buy.
Probably the first.
Yes, it is expensive. But if you are already spending the time and money to paint, this is not the color I would try to save a few dollars on. A good Cobalt Blue is worth it.
Why Cobalt Blue Is So Useful
Because it is such a balanced blue, Cobalt mixes beautifully.
Need a clean green? Mix it with Aureolin, Winsor Yellow, or another transparent yellow.
Need a violet? Add Rose Madder or another cool red.
Need a soft neutral gray? Mix it with Burnt Sienna.
That Burnt Sienna mixture is one of my favorites. Depending on the ratio, you can push it warmer or cooler. More Cobalt gives you a cooler blue-gray. More Burnt Sienna takes it toward a warmer brown-gray.
If I need the mixture even darker, I sometimes add a little Sap Green.
I rarely use tube blacks because I usually find them too flat. I would rather mix a dark that still has some life and color variation in it.
Is Cobalt Blue a Dark Color?
Cobalt Blue is not an especially dark blue.
On a scale of 1 to 10, with 10 being extremely dark, I would probably rate it around a 7.
It has enough strength to create good dark values, but it is not going to give you the same depth as something like Phthalo Blue or Indigo.
That does not bother me.
Its real strength is how well it mixes and how useful it is across so many different subjects.
Does Cobalt Blue Watercolor Granulate?
Cobalt Blue is also slightly granulating.
As the paint dries, some of the pigment settles into the texture of the watercolor paper and creates a subtle speckled pattern.
I love that effect- to me that screams watercolor and is the reason I love the medium.
It works especially well in skies because the wash does not dry completely flat. You get a little texture and movement without the paint becoming overly dramatic.
On cold-pressed or rough paper, it can be especially beautiful.
Cobalt Blue Is Easy to Lift
Another reason Cobalt Blue stays on my palette is that it is relatively non-staining.
If I need to lighten an area, soften an edge, or recover part of a highlight, I can usually go back in with a damp brush and lift quite a bit of the paint.
That makes it a forgiving color to work with, especially in skies, clouds, architecture, and atmospheric passages.
You still need to be careful, obviously, but it gives you more room to make adjustments than a heavily staining blue.
A Little History
Cobalt pigments have been used for a very long time, but the modern Cobalt Blue pigment we know today became much more common in the early 19th century, when a reliable synthetic version was developed.
Before that, strong blue pigments were expensive and difficult to produce, which is one reason you do not see huge amounts of brilliant blue in every old painting.
Blue was valuable.
In many historical paintings, it was reserved for important areas and for works commissioned by people who could afford it.
Thankfully, I do not need a wealthy Renaissance patron to buy a tube now.
Although, looking at the price of some Cobalt paints, it might help.
Why Cobalt Blue Is on Every Palette I Own
Cobalt Blue is one of a very small number of colors I have on every palette.
Every single one.
I use it for skies, water, architecture, shadows, greens, violets, neutral mixtures, and darks.
There are plenty of colors I like.
There are far fewer colors I would consider essential.
Cobalt Blue is one of them.
Do You Need Cobalt Blue?
For me, absolutely.
If you are putting together a watercolor palette and trying to decide where it is worth spending a little more money, this is one of those colors.
It mixes beautifully. It granulates. It lifts easily. It makes excellent skies and useful neutrals. And I use it in some form in almost every painting I make.
Seriously.
You might not love the price.
But you will probably use the paint enough to justify it.
Cobalt Blue is a watercolor essential.
Compare More Watercolor Essential Paints
No single watercolor pigment does everything. Some colors earn their place because they mix beautifully, some granulate, some lift easily, and others create effects that are difficult to reproduce with anything else. Explore more of the watercolor paints I use and compare how they behave:
- Winsor & Newton Ultramarine Blue — A strongly granulating blue that creates beautiful texture, lifts easily, and mixes exceptionally rich darks and near-blacks with Burnt Sienna.
- Winsor & Newton Burnt Sienna — A granulating earth color and one of the workhorses on my palette, especially useful for landscapes, neutral mixtures, and colorful darks.
- Winsor & Newton Cerulean Blue — A cool, green-leaning blue with beautiful granulation and noticeable opacity that I use for atmospheric effects, fog, charging wet washes, and cool accents over darker passages.
- Holbein Sap Green — My favorite natural-looking tube green, with strong granulation, wonderful blossoms, and the ability to create rich, colorful landscape darks.
- Turner Natural Rose Madder — A transparent, low-staining NR9 red that lifts easily and creates beautiful watercolor blossoms. I love how it behaves on paper, but its poor lightfastness means I use it more selectively than my foundational colors.
Every watercolor pigment behaves differently on paper. My Watercolor Essentials reviews look beyond the color in the tube and focus on what actually matters when I’m painting: color bias, transparency, staining, lifting, granulation, blossoms, mixing behavior, and whether the paint really deserves space on my palette.
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Ryan Fox AWS, NWS, TWSA
Ryan Fox Painting
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