Grim Rust vs Transparent Orange

How close are they?

ΔE 9.7, close: similar, with a visible difference side by side. Transparent Orange is a little lighter, more saturated than Grim Rust. They are different kinds of paint: Army Painter Grim Rust is a fluorescent or effect paint and Pro Acryl Transparent Orange is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.

Can I use Transparent Orange instead of Grim Rust?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Transparent Orange is a little lighter, more saturated than Grim Rust. They are different kinds of paint.

Can I use Grim Rust instead of Transparent Orange?

The same difference applies the other way round: Grim Rust is a little darker, more muted.

ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.