Fire Drake vs Phoenix Orange

How close are they?

ΔE 19.4, loose: different enough that you should pick on purpose. Phoenix Orange is noticeably darker, more saturated, cooler than Fire Drake.

Can I use Phoenix Orange instead of Fire Drake?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Phoenix Orange is noticeably darker, more saturated, cooler than Fire Drake.

Can I use Fire Drake instead of Phoenix Orange?

The same difference applies the other way round: Fire Drake is noticeably lighter, more muted, 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.