ΔE 27.1, loose: different enough that you should pick on purpose. Ethereal Green is a little darker, much more muted than Warpstone Glow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 27). Ethereal Green is a little darker, much more muted than Warpstone Glow.
The same difference applies the other way round: Warpstone Glow is a little lighter, much 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.
See Warpstone Glow on the colour wheel See Ethereal Green on the colour wheel
All matches: Warpstone Glow equivalents · Ethereal Green equivalents