ΔE 19.3, loose: different enough that you should pick on purpose. Septic Green is noticeably darker, much more muted than Vivid Volt.
✓ Two Thin Coats comparison chart lists these two as equivalents.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 19). Septic Green is noticeably darker, much more muted than Vivid Volt.
The same difference applies the other way round: Vivid Volt is noticeably 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 Vivid Volt on the colour wheel See Septic Green on the colour wheel
All matches: Vivid Volt equivalents · Septic Green equivalents