Grey Castle vs Medium Sea Gray 2 (RAF)

How close are they?

ΔE 11.9, fair: the same colour family, but not a straight swap. Medium Sea Gray 2 (RAF) is a little lighter than Grey Castle.

Can I use Medium Sea Gray 2 (RAF) instead of Grey Castle?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Medium Sea Gray 2 (RAF) is a little lighter than Grey Castle.

Can I use Grey Castle instead of Medium Sea Gray 2 (RAF)?

The same difference applies the other way round: Grey Castle is a little darker.

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.