ΔE 20.4, loose: different enough that you should pick on purpose. Gladeshard is noticeably darker, more saturated, cooler than Luminous Green.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 20). Gladeshard is noticeably darker, more saturated, cooler than Luminous Green.
The same difference applies the other way round: Luminous Green is noticeably lighter, 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.
See Luminous Green on the colour wheel See Gladeshard on the colour wheel
All matches: Luminous Green equivalents · Gladeshard equivalents