Ordic Olive vs Dirty Grey

How close are they?

ΔE 16.2, loose: different enough that you should pick on purpose. Dirty Grey is a little lighter, more muted, warmer than Ordic Olive.

Can I use Dirty Grey instead of Ordic Olive?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Dirty Grey is a little lighter, more muted, warmer than Ordic Olive.

Can I use Ordic Olive instead of Dirty Grey?

The same difference applies the other way round: Ordic Olive is a little darker, more saturated, 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.