ΔE 11.8, fair: the same colour family, but not a straight swap. Aquamarine is a little lighter, more saturated, warmer than Spirit Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Aquamarine is a little lighter, more saturated, warmer than Spirit Blue.
The same difference applies the other way round: Spirit Blue is a little darker, more muted, 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 Spirit Blue on the colour wheel See Aquamarine on the colour wheel
All matches: Spirit Blue equivalents · Aquamarine equivalents