Turquoise vs Ruinous Spell

How close are they?

ΔE 11.5, fair: the same colour family, but not a straight swap. Ruinous Spell is a little lighter, more saturated, warmer than Turquoise.

Can I use Ruinous Spell instead of Turquoise?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Ruinous Spell is a little lighter, more saturated, warmer than Turquoise.

Can I use Turquoise instead of Ruinous Spell?

The same difference applies the other way round: Turquoise is a little darker, 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.