ΔE 8.3, close: similar, with a visible difference side by side. Fresh Rust is a little darker, more muted than Penetrating Red INK. They are different kinds of paint: AK Interactive Penetrating Red INK is an ink, glaze or transparent paint and Army Painter Fresh Rust is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Fresh Rust is a little darker, more muted than Penetrating Red INK. They are different kinds of paint.
The same difference applies the other way round: Penetrating Red INK is a little lighter, more saturated.
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.
See Penetrating Red INK on the colour wheel See Fresh Rust on the colour wheel
All matches: Penetrating Red INK equivalents · Fresh Rust equivalents