Dark Rust vs Dark Vermilion

How close are they?

ΔE 11.3, fair: the same colour family, but not a straight swap. Dark Vermilion is a little lighter, more saturated, cooler than Dark Rust.

Can I use Dark Vermilion instead of Dark Rust?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Dark Vermilion is a little lighter, more saturated, cooler than Dark Rust.

Can I use Dark Rust instead of Dark Vermilion?

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

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.