ΔE 15.1, loose: different enough that you should pick on purpose. Dark Blue RLM24 is more muted, cooler than Dead Purple.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Dark Blue RLM24 is more muted, cooler than Dead Purple.
The same difference applies the other way round: Dead Purple is more saturated, 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.
See Dead Purple on the colour wheel See Dark Blue RLM24 on the colour wheel
All matches: Dead Purple equivalents · Dark Blue RLM24 equivalents