Ruinous Spell vs Dark Emerald

How close are they?

ΔE 11.8, fair: the same colour family, but not a straight swap. Dark Emerald is a little darker, more muted, cooler than Ruinous Spell.

Can I use Dark Emerald instead of Ruinous Spell?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Dark Emerald is a little darker, more muted, cooler than Ruinous Spell.

Can I use Ruinous Spell instead of Dark Emerald?

The same difference applies the other way round: Ruinous Spell is a little lighter, more saturated, 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.