Infernal Red vs Resplendent Red

How close are they?

ΔE 9.9, close: similar, with a visible difference side by side. Resplendent Red is more saturated, warmer than Infernal Red.

Can I use Resplendent Red instead of Infernal Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Resplendent Red is more saturated, warmer than Infernal Red.

Can I use Infernal Red instead of Resplendent Red?

The same difference applies the other way round: Infernal Red is more muted, cooler.

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.