ΔE 9.4, close: similar, with a visible difference side by side. RLM 78 Light Blue is a little lighter than Tanker Grey.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). RLM 78 Light Blue is a little lighter than Tanker Grey.
The same difference applies the other way round: Tanker Grey is a little darker.
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 Tanker Grey on the colour wheel See RLM 78 Light Blue on the colour wheel
All matches: Tanker Grey equivalents · RLM 78 Light Blue equivalents