ΔE 13.5, fair: the same colour family, but not a straight swap. Faded P.R.U. Blue is a little lighter, more muted, cooler than Turquois (Phthalo).
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Faded P.R.U. Blue is a little lighter, more muted, cooler than Turquois (Phthalo).
The same difference applies the other way round: Turquois (Phthalo) is a little darker, 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 Turquois (Phthalo) on the colour wheel See Faded P.R.U. Blue on the colour wheel
All matches: Turquois (Phthalo) equivalents · Faded P.R.U. Blue equivalents