ΔE 7.9, close: similar, with a visible difference side by side. Ivory is a little darker, more saturated than Insignia White FS 17875.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Ivory is a little darker, more saturated than Insignia White FS 17875.
The same difference applies the other way round: Insignia White FS 17875 is a little lighter, 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 FS 17875 on the colour wheel See Ivory on the colour wheel
All matches: Insignia White FS 17875 equivalents · Ivory equivalents