ΔE 16.5, loose: different enough that you should pick on purpose. C.P. Cadmium Yellow Medium is a little lighter, more saturated, cooler than Phalanx Yellow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). C.P. Cadmium Yellow Medium is a little lighter, more saturated, cooler than Phalanx Yellow.
The same difference applies the other way round: Phalanx Yellow is a little darker, more muted, 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 Phalanx Yellow on the colour wheel See C.P. Cadmium Yellow Medium on the colour wheel
All matches: Phalanx Yellow equivalents · C.P. Cadmium Yellow Medium equivalents