ΔE 12.7, fair: the same colour family, but not a straight swap. Aquamarine is a little darker, more saturated than Light Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Aquamarine is a little darker, more saturated than Light Blue.
The same difference applies the other way round: Light Blue is a little lighter, 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 Light Blue on the colour wheel See Aquamarine on the colour wheel
All matches: Light Blue equivalents · Aquamarine equivalents