ΔE 15.3, loose: different enough that you should pick on purpose. Temple Guard Blue is a little darker, cooler than Hydra Turquoise.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Temple Guard Blue is a little darker, cooler than Hydra Turquoise.
The same difference applies the other way round: Hydra Turquoise is a little lighter, 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 Hydra Turquoise on the colour wheel See Temple Guard Blue on the colour wheel
All matches: Hydra Turquoise equivalents · Temple Guard Blue equivalents