Dark Warm Grey vs Field Blue

How close are they?

ΔE 10.9, fair: the same colour family, but not a straight swap. Field Blue is a little lighter, more saturated than Dark Warm Grey.

Can I use Field Blue instead of Dark Warm Grey?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Field Blue is a little lighter, more saturated than Dark Warm Grey.

Can I use Dark Warm Grey instead of Field Blue?

The same difference applies the other way round: Dark Warm Grey is a little darker, more muted.

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.