ΔE 11.0, fair: the same colour family, but not a straight swap. Cobalt Green is a little darker, more muted, warmer than Sons of Horus Green.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Cobalt Green is a little darker, more muted, warmer than Sons of Horus Green.
The same difference applies the other way round: Sons of Horus Green is a little lighter, more saturated, 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 Sons of Horus Green on the colour wheel See Cobalt Green on the colour wheel
All matches: Sons of Horus Green equivalents · Cobalt Green equivalents