Rust paint in acrylic, oil and watercolor, compared

Recipes by medium

Checked August 2026

Generic pigment ratios, the same ones the Chromilla mixer solves for. Open the mixer to swap in your own brand and tubes.

Common mistakes when mixing rust

Rust is a dark, warm orange-red, and the mistake is starting from bright orange and trying to darken it, which usually just dulls it toward brown too fast. Starting from a red-orange earth pigment (a burnt sienna or similar) and adjusting from there keeps the warmth and darkness together instead of losing one for the other. A little black goes further than people expect here, use less than you think you need.

Exact single-medium recipes

Straight-to-the-ratio versions of rust in each medium, from the Chromilla mix library.

• Rust in acrylic
• Rust in oil
• Rust in watercolor

Why the three mediums differ for rust

• acrylic carries a 10% value shift on drying in Chromilla's model (dries slightly darker and a touch warmer), so the acrylic mix is predicted to dry to #90431D.
• oil dries true to color in Chromilla's model, so the oil mix is predicted to dry to #9D4A22.
• watercolor carries a 8% value shift on drying in Chromilla's model (dries slightly darker and a touch cooler), so the watercolor mix is predicted to dry to #8F4421.
• In watercolor the paper is the white, so lighter versions come from adding water rather than white paint.

Acrylic recipe in detail

Variations on Rust (acrylic)

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.

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.

Related colors

More colours to try once you have rust sorted.

• How to make Terracotta paint/guides/how-to-mix-terracotta
• How to make Burnt Orange paint/guides/how-to-mix-burnt-orange
• How to make Chestnut paint/guides/how-to-mix-chestnut
• How to make Mahogany paint/guides/how-to-mix-mahogany
• How to make Bronze paint/guides/how-to-mix-bronze