WWI German Light Green vs Witch Brew

How close are they?

ΔE 6.7, close: similar, with a visible difference side by side. Witch Brew is a little darker, warmer than WWI German Light Green.

Can I use Witch Brew instead of WWI German Light Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Witch Brew is a little darker, warmer than WWI German Light Green.

Can I use WWI German Light Green instead of Witch Brew?

The same difference applies the other way round: WWI German Light Green 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.