Castellan Green vs Prussian Green

How close are they?

ΔE 14.7, fair: the same colour family, but not a straight swap. Prussian Green is noticeably darker, more muted than Castellan Green.

Can I use Prussian Green instead of Castellan Green?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Prussian Green is noticeably darker, more muted than Castellan Green.

Can I use Castellan Green instead of Prussian Green?

The same difference applies the other way round: Castellan Green is noticeably lighter, 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.