ΔE 22.1, loose: different enough that you should pick on purpose. Ancestral Blue is noticeably lighter, more muted, cooler than Terradon Turquoise.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 22). Ancestral Blue is noticeably lighter, more muted, cooler than Terradon Turquoise.
The same difference applies the other way round: Terradon Turquoise is noticeably 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 Terradon Turquoise on the colour wheel See Ancestral Blue on the colour wheel
All matches: Terradon Turquoise equivalents · Ancestral Blue equivalents