Choosing And Using Cerulean Blue Watercolor Paint

There Are Two Different Cerulean Blues. This Lesson Shows The Difference


  • What can be difficult and confusing about choosing and using this common color

About This Lesson

Cerulean Blue is one of those colors that doesn’t seem to be “standard”. It’s confusing and disappointing buy a color with a familiar name then find that it isn’t what you expected. Unfortunately, colors from different brands that have the same name often look and work very differently.

Cerulean Blue watercolor is one of the offenders. This lesson shows you why and how to insure you are getting the color and results you expect.

The color generally known as “cerulean” goes back to classical times and was referred to as “caerulum“.  Caerulum was the name given to many blue hues and were created from mixtures of copper and cobaltous oxides, like azurite and smalt.

“Modern” cerulean blue was discovered in the 18th century by a Swiss chemist.  It’s Color Index code is PB35 and is valued for its ability represent sky and sky blue.

In more recent times, chemist developed another version of Cerulean blue with a Color Index code of PB36.

The problem for us watercolor artists is that both versions of Cerulean Blue are sold under the same name but look and work differently. Is one better than the other? No. But it’s likely you will prefer one over the other so you need to know just which one you are working with.

This lesson shows and compares the two different versions of Cerulan Blue and shows you how to make sure you are getting the right one.

What you’ll need

  • Winsor Newton Cerulean Blue – Pigment Blue 35 (PB35)
  • DaVinci or Other Brand Cerulean Blue – Pigment Blue 36 (PB36)

More Info About Alizarin Crimson

Centuries ago, artists often made their own paint, using an available pigment, ground very fine and mixed with their choice of medium. In those days, the range of available pigments was limited. Most pigments were made from some organic material. Organic pigments have a number of problems: they are often expensive because of limited supply; they are sometimes not permanent or lightfast; they can be troublesome mixers; and their color range is limited.

Over time, synthetic pigments were developed. The establishment of the chemical pigment industry remedied many of the problems that affect organic pigments.

Still artists were often trained with those familiar organic pigments so the colors themselves got passed along from one generation of artists to the next.

One of the colors that has been popular for centuries is known as Alizarin Crimson. The original Alizarin color was made by extracting a compound from the roots of the madder plant. This compound became the basis for two popular paint colors – Rose Madder and Alizarin Crimson.  Alizarin is a deep, rich red with a blue undertone.  It’s richness, transparency and staining capability has always been valued by artists.

“Real” Alizarin Crimson Is Not Permanent

The problem with the original Alizarin Crimson is that it is not permanent or lightfast. Exposure to the UV rays of light will cause the color to fade or change color and character over time. For artists, this was a cause for concern.

Pigment and paint manufacturers stepped in and created synthetic red pigments that provided a look similar to real Alizarin Crimson. Unfortunately, the real thing is a beautiful and unique color that is hard to duplicate.

For the most part paint manufacturers have done a good job of getting close. Their “Permanent” Alizarin Crimsons are also beautiful colors with blue undertones. The problem for the watercolor artist is that nearly every brand of professional grade Permanent Alizarin Crimson is made with a different pigment or combination of pigments.

In this lesson, we’ll discuss the Permanent Alizarin Crimson “problem” and compare some of the manufacturers colors. We’ll also show you how you can identify what pigments are used to create the color and how to be sure you always get the Permanent Alizarin Crimson you want.