Ethereal Green vs Bright Green

How close are they?

ΔE 7.5, close: similar, with a visible difference side by side. Bright Green is more muted than Ethereal Green.

Can I use Bright Green instead of Ethereal Green?

Usually, if you are not matching paint already on the model. Close match (ΔE 7). Bright Green is more muted than Ethereal Green.

Can I use Ethereal Green instead of Bright Green?

The same difference applies the other way round: Ethereal Green is more saturated.

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.