ΔE 10.1, fair: the same colour family, but not a straight swap. RLM 65 Light Blue is a little darker, more muted than Neptune Glow.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 10). RLM 65 Light Blue is a little darker, more muted than Neptune Glow.
The same difference applies the other way round: Neptune Glow 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 Neptune Glow on the colour wheel See RLM 65 Light Blue on the colour wheel
All matches: Neptune Glow equivalents · RLM 65 Light Blue equivalents