Hellblau RLM 78 vs Celestra Grey

How close are they?

ΔE 13.5, fair: the same colour family, but not a straight swap. Celestra Grey is more muted, cooler than Hellblau RLM 78.

Can I use Celestra Grey instead of Hellblau RLM 78?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Celestra Grey is more muted, cooler than Hellblau RLM 78.

Can I use Hellblau RLM 78 instead of Celestra Grey?

The same difference applies the other way round: Hellblau RLM 78 is more saturated, 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.