ΔE 7.2, close: similar, with a visible difference side by side. Insignia White is a little darker, cooler than Ivory.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Insignia White is a little darker, cooler than Ivory.
The same difference applies the other way round: Ivory is a little lighter, 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.
See Ivory on the colour wheel See Insignia White on the colour wheel
All matches: Ivory equivalents · Insignia White equivalents