ΔE 9.8, close: similar, with a visible difference side by side. Flat Yellow is more saturated than Phalanx Yellow.
Usually, if you are not matching paint already on the model. Close match (ΔE 10). Flat Yellow is more saturated than Phalanx Yellow.
The same difference applies the other way round: Phalanx Yellow is 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 Phalanx Yellow on the colour wheel See Flat Yellow on the colour wheel
All matches: Phalanx Yellow equivalents · Flat Yellow equivalents