Steel Legion Drab vs Chocolate Brown

How close are they?

ΔE 15.9, loose: different enough that you should pick on purpose. Chocolate Brown is a little darker, cooler than Steel Legion Drab.

Can I use Chocolate Brown instead of Steel Legion Drab?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Chocolate Brown is a little darker, cooler than Steel Legion Drab.

Can I use Steel Legion Drab instead of Chocolate Brown?

The same difference applies the other way round: Steel Legion Drab is a little lighter, 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.