ΔE 8.3, close: similar, with a visible difference side by side. Scarlet is a little lighter, more muted than C.P. Cadmium Red Dark.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Scarlet is a little lighter, more muted than C.P. Cadmium Red Dark.
The same difference applies the other way round: C.P. Cadmium Red Dark is a little darker, 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.
See C.P. Cadmium Red Dark on the colour wheel See Scarlet on the colour wheel
All matches: C.P. Cadmium Red Dark equivalents · Scarlet equivalents