ΔE 13.8, fair: the same colour family, but not a straight swap. Rust Brown is a little lighter, more muted, cooler than Molten Orange.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Rust Brown is a little lighter, more muted, cooler than Molten Orange.
The same difference applies the other way round: Molten Orange is a little 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.
See Molten Orange on the colour wheel See Rust Brown on the colour wheel
All matches: Molten Orange equivalents · Rust Brown equivalents