ΔE 15.4, loose: different enough that you should pick on purpose. Kabalite Green is noticeably darker, cooler than Nuclear Sludge.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Kabalite Green is noticeably darker, cooler than Nuclear Sludge.
The same difference applies the other way round: Nuclear Sludge is noticeably lighter, 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 Nuclear Sludge on the colour wheel See Kabalite Green on the colour wheel
All matches: Nuclear Sludge equivalents · Kabalite Green equivalents