ΔE 20.3, loose: different enough that you should pick on purpose. Scurvy Green is a little darker, warmer than Spectral Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Scurvy Green is a little darker, warmer than Spectral Blue.
The same difference applies the other way round: Spectral Blue is a little lighter, 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.
See Spectral Blue on the colour wheel See Scurvy Green on the colour wheel
All matches: Spectral Blue equivalents · Scurvy Green equivalents