Inferno Orange vs Sanctuary Red

How close are they?

ΔE 15.9, loose: different enough that you should pick on purpose. Sanctuary Red is a little darker, more saturated, cooler than Inferno Orange.

Can I use Sanctuary Red instead of Inferno Orange?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Sanctuary Red is a little darker, more saturated, cooler than Inferno Orange.

Can I use Inferno Orange instead of Sanctuary Red?

The same difference applies the other way round: Inferno Orange is a little 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.