ΔE 24.0, loose: different enough that you should pick on purpose. Green Sun is noticeably lighter, more saturated, cooler than Gehenna's Gold.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Green Sun is noticeably lighter, more saturated, cooler than Gehenna's Gold.
The same difference applies the other way round: Gehenna's Gold is noticeably 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.
See Gehenna's Gold on the colour wheel See Green Sun on the colour wheel
All matches: Gehenna's Gold equivalents · Green Sun equivalents