ΔE 8.2, close: similar, with a visible difference side by side. Olive Shadow is a little darker, more saturated, warmer than Tainted Garden.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Olive Shadow is a little darker, more saturated, warmer than Tainted Garden.
The same difference applies the other way round: Tainted Garden is a little lighter, more muted, 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 Tainted Garden on the colour wheel See Olive Shadow on the colour wheel
All matches: Tainted Garden equivalents · Olive Shadow equivalents