Cerulean Blue Watercolor - Not Always The Same!

Cerulean Blue (Cobalt Stannate PB35) at left, Cerulean Blue (Aluminum Oxide PB36) at right

There are two different versions of Cerulean Blue available for purchase. Unfortunately, manufacturers use the same name on these two very different colors. It is confusing for artists and can cause unexpected and unwanted results.

All manufacturers make a version of Cerulean Blue. Some make two versions. The confusing part is that there are two different pigments used for tubes of paint that are called Cerulean Blue.

The difference is clear when swatches of each are placed side-by-side - you can see clearly they're not actually the same color. The difference is in the underlying pigment.

I prefer the traditional version of Cerulean Blue made with PB35 pigment. I use the Winsor-Newton brand, but the PB35 version is produced by other manufacturers as well.

The other version is a newer version made with Pigment Blue 36 or PB 36.

The traditional color (PB35) is very cool, meaning it leans toward green. In fact it can accurately be described as a very green blue. This version has the the unique asset of being highly granular - the pigment leaves distinct texture quality in washes. This is due to the relatively large and heavy pigment particles.

The other version is made with pigment PB36. It is ‘bluer’ in hue and lacks any distinct textural character.

Now, both of those colors are professional grade colors will work just fine in whatever mixtures you want to use them for.

For comparison of their relative hue, they are shown next to Cobalt Blue (PB28), which is nearly a true blue.

The short video below discusses the differences.