ΔE 13.1, fair: the same colour family, but not a straight swap. Ice Yellow is a little lighter, much more saturated than Ivory.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Ice Yellow is a little lighter, much more saturated than Ivory.
The same difference applies the other way round: Ivory is a little darker, much 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 Ivory on the colour wheel See Ice Yellow on the colour wheel
All matches: Ivory equivalents · Ice Yellow equivalents