Red Fluor vs Fluorescent Orange

How close are they?

ΔE 6.6, close: similar, with a visible difference side by side. Fluorescent Orange is more saturated than Red Fluor.

Can I use Fluorescent Orange instead of Red Fluor?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Fluorescent Orange is more saturated than Red Fluor.

Can I use Red Fluor instead of Fluorescent Orange?

The same difference applies the other way round: Red Fluor is 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.