ΔE 11.5, fair: the same colour family, but not a straight swap. RLM 65 Light Blue is a little darker, more muted than Aquamarine.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). RLM 65 Light Blue is a little darker, more muted than Aquamarine.
The same difference applies the other way round: Aquamarine is a little lighter, more saturated.
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 Aquamarine on the colour wheel See RLM 65 Light Blue on the colour wheel
All matches: Aquamarine equivalents · RLM 65 Light Blue equivalents