ΔE 16.0, loose: different enough that you should pick on purpose. Granite Grey is a little lighter, much more muted than Sylvaneth Bark.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Granite Grey is a little lighter, much more muted than Sylvaneth Bark.
The same difference applies the other way round: Sylvaneth Bark is a little darker, much 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 Sylvaneth Bark on the colour wheel See Granite Grey on the colour wheel
All matches: Sylvaneth Bark equivalents · Granite Grey equivalents