ΔE 13.6, fair: the same colour family, but not a straight swap. Phalanx Yellow is a little lighter, more saturated, warmer than Poison Yellow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Phalanx Yellow is a little lighter, more saturated, warmer than Poison Yellow.
The same difference applies the other way round: Poison Yellow is a little darker, 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 Poison Yellow on the colour wheel See Phalanx Yellow on the colour wheel
All matches: Poison Yellow equivalents · Phalanx Yellow equivalents