ΔE 7.7, close: similar, with a visible difference side by side. Ice Yellow is more saturated, warmer than Ivory.
Usually, if you are not matching paint already on the model. Close match (ΔE 8). Ice Yellow is more saturated, warmer than Ivory.
The same difference applies the other way round: Ivory is more muted, cooler.
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 Ice Yellow on the colour wheel
All matches: Ivory equivalents · Ice Yellow equivalents