ΔE 14.9, fair: the same colour family, but not a straight swap. Landser Grey is a little darker, more muted than Turnbull Turquoise.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Landser Grey is a little darker, more muted than Turnbull Turquoise.
The same difference applies the other way round: Turnbull Turquoise is a little lighter, 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 Turnbull Turquoise on the colour wheel See Landser Grey on the colour wheel
All matches: Turnbull Turquoise equivalents · Landser Grey equivalents