Fuchsia vs Hot Pink

How close are they?

ΔE 18.0, loose: different enough that you should pick on purpose. Hot Pink is a little lighter, much more muted than Fuchsia.

Can I use Hot Pink instead of Fuchsia?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Hot Pink is a little lighter, much more muted than Fuchsia.

Can I use Fuchsia instead of Hot Pink?

The same difference applies the other way round: Fuchsia is a little darker, much more saturated.

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.