WWI German Lilac vs Violet Coven

How close are they?

ΔE 9.8, close: similar, with a visible difference side by side. Violet Coven is a little lighter, more saturated, cooler than WWI German Lilac.

Can I use Violet Coven instead of WWI German Lilac?

Usually, if you are not matching paint already on the model. Close match (ΔE 10). Violet Coven is a little lighter, more saturated, cooler than WWI German Lilac.

Can I use WWI German Lilac instead of Violet Coven?

The same difference applies the other way round: WWI German Lilac is a little darker, more muted, warmer.

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.