ΔE 16.9, loose: different enough that you should pick on purpose. Leather Brown is a little darker, more muted, cooler than Flaming Forge Orange.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Leather Brown is a little darker, more muted, cooler than Flaming Forge Orange.
The same difference applies the other way round: Flaming Forge Orange is a little lighter, 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 Flaming Forge Orange on the colour wheel See Leather Brown on the colour wheel
All matches: Flaming Forge Orange equivalents · Leather Brown equivalents