Medium Green vs Castellan Green

How close are they?

ΔE 10.1, fair: the same colour family, but not a straight swap. Castellan Green is a little lighter, more saturated, cooler than Medium Green.

Can I use Castellan Green instead of Medium Green?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Castellan Green is a little lighter, more saturated, cooler than Medium Green.

Can I use Medium Green instead of Castellan Green?

The same difference applies the other way round: Medium Green is a little darker, more muted, 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.