Dark Brown vs Light Rust

How close are they?

ΔE 12.8, fair: the same colour family, but not a straight swap. Light Rust is noticeably lighter, more muted, cooler than Dark Brown.

Can I use Light Rust instead of Dark Brown?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Light Rust is noticeably lighter, more muted, cooler than Dark Brown.

Can I use Dark Brown instead of Light Rust?

The same difference applies the other way round: Dark Brown is noticeably darker, more saturated, 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.