ΔE 8.3, close: similar, with a visible difference side by side. Malefic Flesh is a little darker, more saturated, warmer than Red Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Malefic Flesh is a little darker, more saturated, warmer than Red Grey.
The same difference applies the other way round: Red Grey 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 Red Grey on the colour wheel See Malefic Flesh on the colour wheel
All matches: Red Grey equivalents · Malefic Flesh equivalents