ΔE 63.3, poor: a clearly different colour, so not a substitute. Satin Varnish is noticeably lighter than Primer Dark Neutral Grey.
Not as a straight swap; see the closer alternatives below. Poor match (ΔE 63). Satin Varnish is noticeably lighter than Primer Dark Neutral Grey.
The same difference applies the other way round: Primer Dark Neutral Grey is noticeably darker.
ΔE is the colour difference between our two swatch estimates: under 2 is a perfect match (you’d struggle to tell them apart), under 6 very close, under 10 close, under 15 fair, under 20 loose, under 30 very loose, and 30 or more a poor match. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Primer Dark Neutral Grey on the colour wheel See Satin Varnish on the colour wheel
All matches: Primer Dark Neutral Grey equivalents · Satin Varnish equivalents