ΔE 12.9, fair: the same colour family, but not a straight swap. Copper is more muted, cooler than Life On Mars.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Copper is more muted, cooler than Life On Mars.
The same difference applies the other way round: Life On Mars is 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.
See Life On Mars on the colour wheel See Copper on the colour wheel
All matches: Life On Mars equivalents · Copper equivalents