ΔE 42.1, loose: different enough that you should pick on purpose. Graphite Grey is noticeably darker, more muted than Ashen Stone.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 42). Graphite Grey is noticeably darker, more muted than Ashen Stone.
The same difference applies the other way round: Ashen Stone is noticeably lighter, more saturated.
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 Ashen Stone on the colour wheel See Graphite Grey on the colour wheel
All matches: Ashen Stone equivalents · Graphite Grey equivalents