ΔE 17.9, loose: different enough that you should pick on purpose. Mythic Turquoise is more muted, warmer than Skink Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Mythic Turquoise is more muted, warmer than Skink Blue.
The same difference applies the other way round: Skink Blue is more saturated, cooler.
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 Skink Blue on the colour wheel See Mythic Turquoise on the colour wheel
All matches: Skink Blue equivalents · Mythic Turquoise equivalents