ΔE 11.4, fair: the same colour family, but not a straight swap. Cayman Green is a little darker, more muted than Dune Shadow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Cayman Green is a little darker, more muted than Dune Shadow.
The same difference applies the other way round: Dune Shadow is a little 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.
See Dune Shadow on the colour wheel See Cayman Green on the colour wheel
All matches: Dune Shadow equivalents · Cayman Green equivalents