Administratum Grey vs Grey Blue RLM84

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Grey Blue RLM84 is a little lighter, more saturated than Administratum Grey.

Can I use Grey Blue RLM84 instead of Administratum Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Grey Blue RLM84 is a little lighter, more saturated than Administratum Grey.

Can I use Administratum Grey instead of Grey Blue RLM84?

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