Administratum Grey vs Frost Blue

How close are they?

ΔE 9.5, close: similar, with a visible difference side by side. Frost Blue is more saturated than Administratum Grey.

Can I use Frost Blue instead of Administratum Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 9). Frost Blue is more saturated than Administratum Grey.

Can I use Administratum Grey instead of Frost Blue?

The same difference applies the other way round: Administratum Grey is 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.