ΔE 15.6, loose: different enough that you should pick on purpose. Toxic Mist is noticeably lighter, more saturated, cooler than Spectral Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Toxic Mist is noticeably lighter, more saturated, cooler than Spectral Blue.
The same difference applies the other way round: Spectral Blue is noticeably darker, more muted, 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 Spectral Blue on the colour wheel See Toxic Mist on the colour wheel
All matches: Spectral Blue equivalents · Toxic Mist equivalents