Longbeard Grey vs Ivory Tusk

How close are they?

ΔE 8.3, close: similar, with a visible difference side by side. Ivory Tusk is a little lighter than Longbeard Grey.

Can I use Ivory Tusk instead of Longbeard Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Ivory Tusk is a little lighter than Longbeard Grey.

Can I use Longbeard Grey instead of Ivory Tusk?

The same difference applies the other way round: Longbeard 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.