Celestra Grey vs Medium Seagray BS637

How close are they?

ΔE 9.5, close: similar, with a visible difference side by side. Medium Seagray BS637 is a little darker than Celestra Grey.

Can I use Medium Seagray BS637 instead of Celestra Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Medium Seagray BS637 is a little darker than Celestra Grey.

Can I use Celestra Grey instead of Medium Seagray BS637?

The same difference applies the other way round: Celestra 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.