Deep Khaki Drill vs Warm Brown

How close are they?

ΔE 17.1, loose: different enough that you should pick on purpose. Warm Brown is a little darker, much more saturated, warmer than Deep Khaki Drill.

Can I use Warm Brown instead of Deep Khaki Drill?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Warm Brown is a little darker, much more saturated, warmer than Deep Khaki Drill.

Can I use Deep Khaki Drill instead of Warm Brown?

The same difference applies the other way round: Deep Khaki Drill is a little lighter, much more muted, cooler.

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.