Dark Green Blue vs Wicked Purple

How close are they?

ΔE 21.0, loose: different enough that you should pick on purpose. Wicked Purple is a little lighter, more muted than Dark Green Blue.

Can I use Wicked Purple instead of Dark Green Blue?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Wicked Purple is a little lighter, more muted than Dark Green Blue.

Can I use Dark Green Blue instead of Wicked Purple?

The same difference applies the other way round: Dark Green Blue is a little darker, 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.