ΔE 19.2, loose: different enough that you should pick on purpose. Weathered Blue is noticeably darker, much more muted than Baharroth Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Weathered Blue is noticeably darker, much more muted than Baharroth Blue.
The same difference applies the other way round: Baharroth Blue is noticeably lighter, 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 Baharroth Blue on the colour wheel See Weathered Blue on the colour wheel
All matches: Baharroth Blue equivalents · Weathered Blue equivalents