Faded Orange vs Orange Fire

How close are they?

ΔE 15.4, loose: different enough that you should pick on purpose. Orange Fire is a little darker, much more saturated than Faded Orange.

Can I use Orange Fire instead of Faded Orange?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Orange Fire is a little darker, much more saturated than Faded Orange.

Can I use Faded Orange instead of Orange Fire?

The same difference applies the other way round: Faded Orange is a little lighter, much more muted.

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.