Deep Azure vs Woodland Green

How close are they?

ΔE 23.3, loose: different enough that you should pick on purpose. Woodland Green is a little darker, much more muted than Deep Azure.

Can I use Woodland Green instead of Deep Azure?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Woodland Green is a little darker, much more muted than Deep Azure.

Can I use Deep Azure instead of Woodland Green?

The same difference applies the other way round: Deep Azure is a little lighter, much more saturated.

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.