ΔE 13.7, fair: the same colour family, but not a straight swap. Flat Yellow is more muted, cooler than Peach.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Flat Yellow is more muted, cooler than Peach.
The same difference applies the other way round: Peach is more saturated, 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 Peach on the colour wheel See Flat Yellow on the colour wheel
All matches: Peach equivalents · Flat Yellow equivalents