ΔE 29.7, loose: different enough that you should pick on purpose. Spectral Blue is much more muted, cooler than Teclis Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 30). Spectral Blue is much more muted, cooler than Teclis Blue.
The same difference applies the other way round: Teclis Blue is much 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 Teclis Blue on the colour wheel See Spectral Blue on the colour wheel
All matches: Teclis Blue equivalents · Spectral Blue equivalents