ΔE 10.3, fair: the same colour family, but not a straight swap. Ivory is a little lighter, more saturated than Insignia White (US Navy).
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Ivory is a little lighter, more saturated than Insignia White (US Navy).
The same difference applies the other way round: Insignia White (US Navy) 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.
See Insignia White (US Navy) on the colour wheel See Ivory on the colour wheel
All matches: Insignia White (US Navy) equivalents · Ivory equivalents