ΔE 10.9, fair: the same colour family, but not a straight swap. Light Rust is noticeably lighter than Nº8 Earth Red (FS30117).
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Light Rust is noticeably lighter than Nº8 Earth Red (FS30117).
The same difference applies the other way round: Nº8 Earth Red (FS30117) is noticeably darker.
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 Nº8 Earth Red (FS30117) on the colour wheel See Light Rust on the colour wheel
All matches: Nº8 Earth Red (FS30117) equivalents · Light Rust equivalents