Lighter Cobalt Blue
#4364B3
7 parts Ultramarine Blue, 3 parts Titanium White and 1 part Phthalo Blue. Chromilla's model predicts a 91% dry match against the target, scored against its own color model, not a measured paint-out.
How to Mix Cobalt Blue in Acrylic
Quick answer
To mix cobalt blue (#2E4C99) in acrylic, use 12 parts Ultramarine Blue, 5 parts Phthalo Blue and 3 parts Titanium White. Chromilla's model predicts a 93% dry match against the target, scored against its own color model, not a measured paint-out. Chromilla is a web-based paint color mixer that turns any color, from a photo, the camera or a hex code, into exact paint-tube ratios for acrylic, oil and watercolor, using Kubelka-Munk pigment mixing and aiming at the color after it dries.
Target
Cobalt Blue
#2E4C99
Predicted dry result
93% match when dryMix to #224BA1 while wet. It dries to about #22448F.
| Paint | Pigment | Parts | Share | 100 ml batch |
|---|---|---|---|---|
| Ultramarine Blue | PB29 | 12 | 59% | 59 ml |
| Phthalo Blue | PB15 | 5 | 26% | 26 ml |
| Titanium White | PW6 | 3 | 15% | 15 ml |
How we calculated this: Kubelka-Munk pigment mixing, then a per-medium dry shift, scored with CIEDE2000. Method and accuracy benchmark. Last checked August 2026.
Terms used here: Tinting strength, Dry shift, Kubelka-Munk, Delta E (dE2000), Pigment code, Gamut.
A pure, mid-value blue. Neutral leaning (neither warm nor cool). This guide gives you the pigment ratios that land on #2E4C99 in acrylic, using the same solver that powers the Chromilla mixer.
Pigment recipe
Checked August 2026
Ratios calibrated for acrylic. Start with the dominant pigment, add the modifiers in the order below, and adjust in 5% steps to your target swatch.
1. Ultramarine Blue
PB29
59%2. Phthalo Blue
PB15
26%3. Titanium White
PW6
15%
What colors make Cobalt Blue?
Ultramarine Blue, Phthalo Blue, and Titanium White, in roughly a 59:26:15 ratio.
How to make Cobalt Blue in acrylic
Start with Ultramarine Blue at about 59% as your acrylic base, then work in Phthalo Blue and Titanium White in the order above. Adjust in 5% steps until the swatch reads #2E4C99.
Why mix Cobalt Blue instead of buying it
Mixing Cobalt Blue yourself lets you approximate an expensive or hard to find tube from pigments you already own, match Cobalt Blue across paint brands whose factory tubes differ, and rebuild the exact color when you run out mid painting. The recipe above is the working starting point.
Common mistakes
That pigment is a very strong tinter, add it a touch at a time or it will swallow the mix. White cools and chalks a mix as you add it, so tint in small steps and stop before it goes pastel.
Variations on Cobalt Blue
Each variation is its own target (lighter and darker move OKLCH lightness by 0.08; warmer and cooler turn the hue 12 degrees toward red or blue), solved fresh.
Darker Cobalt Blue
#1A3580
8 parts Ultramarine Blue, 4 parts Viridian Green and 1 part Phthalo Blue. Chromilla's model predicts a 93% dry match against the target, scored against its own color model, not a measured paint-out.
Warmer Cobalt Blue
#424698
85% Ultramarine Blue, 12% Titanium White and 3% Alizarin Crimson. Chromilla's model predicts a 91% dry match against the target, scored against its own color model, not a measured paint-out.
Cooler Cobalt Blue
#2B4D99
3 parts Ultramarine Blue, 2 parts Phthalo Blue and 1 part Titanium White. Chromilla's model predicts a 92% dry match against the target, scored against its own color model, not a measured paint-out.
Cobalt Blue questions
- What two colors make cobalt blue?
- Chromilla's acrylic recipe uses 3 tubes rather than two: 12 parts Ultramarine Blue, 5 parts Phthalo Blue and 3 parts Titanium White. Ultramarine Blue leads the mix. Chromilla's model predicts a 93% dry match against the target, scored against its own color model, not a measured paint-out.
- How do you make cobalt blue paint lighter without losing the hue?
- Re-balance the mix instead of only adding white. For a lighter cobalt blue (#4364B3) in acrylic, Chromilla mixes 7 parts Ultramarine Blue, 3 parts Titanium White and 1 part Phthalo Blue. Chromilla's model predicts a 91% dry match against the target, scored against its own color model, not a measured paint-out.
- Why does cobalt blue look different when acrylic dries?
- Acrylic binder looks milky while wet and clears as it dries, so the dried film reads darker. Chromilla's model applies a 10% value shift for acrylic, so the wet mix #224BA1 is predicted to dry to about #22448F. Dries slightly darker and a touch warmer.
- What is the hex code for cobalt blue?
- Chromilla uses #2E4C99 as the target for cobalt blue. The acrylic recipe is predicted to dry to about #22448F.
- Can I mix cobalt blue without black?
- Yes. Chromilla's acrylic recipe uses no black: 12 parts Ultramarine Blue, 5 parts Phthalo Blue and 3 parts Titanium White.
Cobalt Blue in other mediums
- Cobalt Blue in Oil: 12 parts Ultramarine Blue, 5 parts Phthalo Blue and 3 parts Titanium White, predicted 96% dry match by Chromilla's color model.
- Cobalt Blue in Watercolor: 12 parts Ultramarine Blue, 5 parts Phthalo Blue and 3 parts Titanium White, predicted 94% dry match by Chromilla's color model.
Get this recipe for your paint brand
Open the live mixer with Cobalt Blue + acrylic pre-loaded and calibrate to your tubes.
Technique guides for this color
Related mixing guides
Pigment mixing is subtractive, so small ratio changes matter. The mixer refines this recipe to your brand and updates on the fly.