Resplendent Red vs Carmine Blades

How close are they?

ΔE 8.9, close: similar, with a visible difference side by side. Carmine Blades is a little darker, cooler than Resplendent Red.

Can I use Carmine Blades instead of Resplendent Red?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Carmine Blades is a little darker, cooler than Resplendent Red.

Can I use Resplendent Red instead of Carmine Blades?

The same difference applies the other way round: Resplendent Red is a little lighter, 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.