ΔE 19.6, loose: different enough that you should pick on purpose. Payne’s Grey is noticeably darker, much more muted, warmer than Ahriman Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Payne’s Grey is noticeably darker, much more muted, warmer than Ahriman Blue.
The same difference applies the other way round: Ahriman Blue is noticeably lighter, much more saturated, 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 Ahriman Blue on the colour wheel See Payne’s Grey on the colour wheel
All matches: Ahriman Blue equivalents · Payne’s Grey equivalents