ΔE 13.1, fair: the same colour family, but not a straight swap. Aquamarine is noticeably darker, cooler than Cloud Blue.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Aquamarine is noticeably darker, cooler than Cloud Blue.
The same difference applies the other way round: Cloud Blue is noticeably lighter, 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 Cloud Blue on the colour wheel See Aquamarine on the colour wheel
All matches: Cloud Blue equivalents · Aquamarine equivalents