ΔE 15.2, loose: different enough that you should pick on purpose. IDF Blue is a little lighter, much more muted than Tidal Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). IDF Blue is a little lighter, much more muted than Tidal Blue.
The same difference applies the other way round: Tidal Blue is a little darker, much 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 Tidal Blue on the colour wheel See IDF Blue on the colour wheel
All matches: Tidal Blue equivalents · IDF Blue equivalents