ΔE 35.6, loose: different enough that you should pick on purpose. Zombie Skin is more muted, warmer than Thunderbird Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 36). Zombie Skin is more muted, warmer than Thunderbird Blue.
The same difference applies the other way round: Thunderbird 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 Thunderbird Blue on the colour wheel See Zombie Skin on the colour wheel
All matches: Thunderbird Blue equivalents · Zombie Skin equivalents