Bright Brown Grey vs AMT-1 Lt. Grey. Brown

How close are they?

ΔE 6.2, close: similar, with a visible difference side by side. AMT-1 Lt. Grey. Brown is a little darker than Bright Brown Grey.

Can I use AMT-1 Lt. Grey. Brown instead of Bright Brown Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). AMT-1 Lt. Grey. Brown is a little darker than Bright Brown Grey.

Can I use Bright Brown Grey instead of AMT-1 Lt. Grey. Brown?

The same difference applies the other way round: Bright Brown Grey is a little lighter.

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.