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