Ash Grey vs Bastion Grey

How close are they?

ΔE 20.3, loose: different enough that you should pick on purpose. Bastion Grey is noticeably darker, much more saturated than Ash Grey.

Can I use Bastion Grey instead of Ash Grey?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Bastion Grey is noticeably darker, much more saturated than Ash Grey.

Can I use Ash Grey instead of Bastion Grey?

The same difference applies the other way round: Ash Grey is noticeably lighter, much more muted.

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.