Kobold Grey vs Stone Grey

How close are they?

ΔE 8.0, close: similar, with a visible difference side by side. Stone Grey is a little darker, warmer than Kobold Grey.

Can I use Stone Grey instead of Kobold Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Stone Grey is a little darker, warmer than Kobold Grey.

Can I use Kobold Grey instead of Stone Grey?

The same difference applies the other way round: Kobold Grey is a little lighter, cooler.

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.