Pigment pair · PB35 + PB15:3
Mixing Cerulean Blue and Phthalo Blue
Nine steps from one to the other, worked out with a spectral model rather than by averaging screen colors. Half and half gives #17527E. Click any step to open it in the mixer.
The full range, Cerulean Blue to Phthalo Blue
Ratios are parts by volume, the way you would put them out on a palette.
These two are close enough on the color wheel that they never cancel. Every mixture between them keeps its saturation, so this is a pair for building color, not for knocking it back.
The same range with white added
Two parts titanium white to one part of the mixture above. White lifts the value but also takes the chroma down, which is why a tint is never simply a lighter version of the same color.
The same range as a watercolor wash
Roughly one part paint to two parts water, over white paper. Remember that watercolor dries up to about thirty per cent lighter than it looks while wet.
Phthalo Blue is much the stronger of the two. The ratios above are by volume, so the first step away from pure Phthalo Blue already changes a lot less than the last step towards it. Put out less than looks right and work towards the color; going back costs far more paint.
What you are working with
| Pigment | Index | Strength | Opacity | Lightfast | In |
|---|---|---|---|---|---|
| Cerulean Blue | PB35 | 3/10 | opaque, granulating | excellent | Oil, Watercolor |
| Phthalo Blue | PB15:3 | 10/10 | transparent | excellent | Oil, Watercolor |
Cool, grainy and weak. For skies near the horizon and for cool half-tones.
Extremely strong. Always start with a fraction of what looks right; it takes over any mixture.
Now do it with your own paints
This page assumes two tubes. The mixer works from everything on your palette at once, and from a color you pick out of your own photo.