ΔE 24.1, loose: different enough that you should pick on purpose. Sky Blue is a little darker, more saturated, warmer than Aegis Aqua.
✓ Herrick Games paint comparison chart lists these two as equivalents.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Sky Blue is a little darker, more saturated, warmer than Aegis Aqua.
The same difference applies the other way round: Aegis Aqua is a little lighter, 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 Aegis Aqua on the colour wheel See Sky Blue on the colour wheel
All matches: Aegis Aqua equivalents · Sky Blue equivalents