Soulblight Grey vs Oblivion Black Wash

How close are they?

ΔE 7.9, close: similar, with a visible difference side by side. Oblivion Black Wash is a little darker than Soulblight Grey.

Can I use Oblivion Black Wash instead of Soulblight Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 8). Oblivion Black Wash is a little darker than Soulblight Grey.

Can I use Soulblight Grey instead of Oblivion Black Wash?

The same difference applies the other way round: Soulblight 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.