ΔE 6.5, close: similar, with a visible difference side by side. Parched Grass (Late) is more saturated, warmer than Eidolon Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Parched Grass (Late) is more saturated, warmer than Eidolon Grey.
The same difference applies the other way round: Eidolon Grey is 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 Eidolon Grey on the colour wheel See Parched Grass (Late) on the colour wheel
All matches: Eidolon Grey equivalents · Parched Grass (Late) equivalents