ΔE 76.9, poor: a clearly different colour, so not a substitute. Matt Varnish is noticeably lighter, much more muted than Primer Dark Purple.
Not as a straight swap; see the closer alternatives below. Poor match (ΔE 77). Matt Varnish is noticeably lighter, much more muted than Primer Dark Purple.
The same difference applies the other way round: Primer Dark Purple is noticeably darker, much more saturated.
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 Purple on the colour wheel See Matt Varnish on the colour wheel
All matches: Primer Dark Purple equivalents · Matt Varnish equivalents