ΔE 10.5, fair: the same colour family, but not a straight swap. Flat Earth is a little darker, more muted than Earth Clay.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). Flat Earth is a little darker, more muted than Earth Clay.
The same difference applies the other way round: Earth Clay is a little lighter, more saturated.
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 Earth Clay on the colour wheel See Flat Earth on the colour wheel
All matches: Earth Clay equivalents · Flat Earth equivalents