Luminous Orange vs Lava Orange

How close are they?

ΔE 9.5, close: similar, with a visible difference side by side. Lava Orange is a little darker, more saturated than Luminous Orange.

Can I use Lava Orange instead of Luminous Orange?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Lava Orange is a little darker, more saturated than Luminous Orange.

Can I use Luminous Orange instead of Lava Orange?

The same difference applies the other way round: Luminous Orange is a little lighter, 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.