Molten Orange vs Brown

How close are they?

ΔE 16.5, loose: different enough that you should pick on purpose. Brown is much more muted, cooler than Molten Orange.

Can I use Brown instead of Molten Orange?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Brown is much more muted, cooler than Molten Orange.

Can I use Molten Orange instead of Brown?

The same difference applies the other way round: Molten Orange is much 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.