ΔE 14.6, fair: the same colour family, but not a straight swap. Grey Blue RLM84 is noticeably lighter, more saturated than N5 Neutral Gray.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Grey Blue RLM84 is noticeably lighter, more saturated than N5 Neutral Gray.
The same difference applies the other way round: N5 Neutral Gray is noticeably darker, 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 N5 Neutral Gray on the colour wheel See Grey Blue RLM84 on the colour wheel
All matches: N5 Neutral Gray equivalents · Grey Blue RLM84 equivalents