Steel Helmet Green vs Bastion Grey

How close are they?

ΔE 16.1, loose: different enough that you should pick on purpose. Bastion Grey is noticeably lighter, more muted, cooler than Steel Helmet Green.

Can I use Bastion Grey instead of Steel Helmet Green?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Bastion Grey is noticeably lighter, more muted, cooler than Steel Helmet Green.

Can I use Steel Helmet Green instead of Bastion Grey?

The same difference applies the other way round: Steel Helmet Green is noticeably darker, more saturated, warmer.

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.