ΔE 19.3, loose: different enough that you should pick on purpose. Crimson Hell is a little lighter, more muted, cooler than Strong Skin Wash. They are different kinds of paint: Army Painter Strong Skin Wash is a wash/shade and Nocturna Models Crimson Hell is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Crimson Hell is a little lighter, more muted, cooler than Strong Skin Wash. They are different kinds of paint.
The same difference applies the other way round: Strong Skin Wash is a little darker, more saturated, warmer.
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 Strong Skin Wash on the colour wheel See Crimson Hell on the colour wheel
All matches: Strong Skin Wash equivalents · Crimson Hell equivalents