Grotesque Green vs Gray FS26440

How close are they?

ΔE 10.2, fair: the same colour family, but not a straight swap. Gray FS26440 is a little darker, more muted, cooler than Grotesque Green.

Can I use Gray FS26440 instead of Grotesque Green?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Gray FS26440 is a little darker, more muted, cooler than Grotesque Green.

Can I use Grotesque Green instead of Gray FS26440?

The same difference applies the other way round: Grotesque Green 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.