Chromilla paint mixing tool

How to Mix Rust in Acrylic

Quick answer

To mix rust (#9C4A24) in acrylic, use 60% Yellow Ochre, 31% Raw Umber and 9% Alizarin Crimson. Chromilla's model predicts a 92% 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.

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Target

Rust

#9C4A24

Predicted dry result

92% match when dry

Mix to #9D4A22 while wet. It dries to about #90431D.

Rust in acrylic: tube ratios, and ml for a 100 ml batch
PaintPigmentShare100 ml batch
Yellow OchrePY4360%60 ml
Raw UmberPBr731%31 ml
Alizarin CrimsonPR839%9 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 burnt orange-brown rust. This guide gives you the pigment ratios that land on #9C4A24 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. 1. Yellow Ochre

    PY43

    60%

  2. 2. Raw Umber

    PBr7

    31%

  3. 3. Alizarin Crimson

    PR83

    9%

What colors make Rust?

Yellow Ochre, Raw Umber, and Alizarin Crimson, in roughly a 60:31:9 ratio.

How to make Rust in acrylic

Start with Yellow Ochre at about 60% as your acrylic base, then work in Raw Umber and Alizarin Crimson in the order above. Adjust in 5% steps until the swatch reads #9C4A24.

Why mix Rust instead of buying it

Mixing Rust yourself lets you approximate an expensive or hard to find tube from pigments you already own, match Rust 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

Overshooting on Yellow Ochre is the usual failure, add it in 5% steps and compare against the target between each pass.

Variations on Rust

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.

Lighter Rust

#B6623C

91% Yellow Ochre, 5% Alizarin Crimson and 4% Burnt Umber. Chromilla's model predicts an 89% dry match against the target, scored against its own color model, not a measured paint-out.

Darker Rust

#823306

7 parts Burnt Sienna to 1 part Burnt Umber. Chromilla's model predicts a 94% dry match against the target, scored against its own color model, not a measured paint-out.

Warmer Rust

#9E4637

8 parts Cadmium Red, 3 parts Titanium White and 1 part Ultramarine Blue. Chromilla's model predicts a 91% dry match against the target, scored against its own color model, not a measured paint-out.

Cooler Rust

#9E4637

8 parts Cadmium Red, 3 parts Titanium White and 1 part Ultramarine Blue. Chromilla's model predicts a 91% dry match against the target, scored against its own color model, not a measured paint-out.

Rust questions

What two colors make rust?
Chromilla's acrylic recipe uses 3 tubes rather than two: 60% Yellow Ochre, 31% Raw Umber and 9% Alizarin Crimson. Yellow Ochre leads the mix. Chromilla's model predicts a 92% dry match against the target, scored against its own color model, not a measured paint-out.
How do you make rust paint lighter without losing the hue?
Re-balance the mix instead of only adding white. For a lighter rust (#B6623C) in acrylic, Chromilla mixes 91% Yellow Ochre, 5% Alizarin Crimson and 4% Burnt Umber. Chromilla's model predicts an 89% dry match against the target, scored against its own color model, not a measured paint-out.
Why does rust 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 #9D4A22 is predicted to dry to about #90431D. Dries slightly darker and a touch warmer.
What is the hex code for rust?
Chromilla uses #9C4A24 as the target for rust. The acrylic recipe is predicted to dry to about #90431D.
Can I mix rust without black?
Yes. Chromilla's acrylic recipe uses no black: 60% Yellow Ochre, 31% Raw Umber and 9% Alizarin Crimson.

Rust in other mediums

  • Rust in Oil: 60% Yellow Ochre, 31% Raw Umber and 9% Alizarin Crimson, predicted 99% dry match by Chromilla's color model.
  • Rust in Watercolor: 60% Yellow Ochre, 31% Raw Umber and 9% Alizarin Crimson, predicted 92% dry match by Chromilla's color model.

Compare acrylic, oil and watercolor for rust

Get this recipe for your paint brand

Open the live mixer with Rust + acrylic pre-loaded and calibrate to your tubes.

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Deep-dive guide

How to mix Rust, the long version

Common mistakes, per-brand recipes, and the honest limits when the target sits outside what real paint can reach.

Read the guide

New to browns? See what colors make brown, in plain terms.

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.