Graphite Grey vs Wicked Purple

How close are they?

ΔE 6.2, close: similar, with a visible difference side by side. Wicked Purple is more saturated than Graphite Grey.

Can I use Wicked Purple instead of Graphite Grey?

Usually, if you are not matching paint already on the model. Close match (ΔE 6). Wicked Purple is more saturated than Graphite Grey.

Can I use Graphite Grey instead of Wicked Purple?

The same difference applies the other way round: Graphite Grey is more muted.

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.