Lens Flare Glow vs Septic Green

How close are they?

ΔE 35.0, loose: different enough that you should pick on purpose. Septic Green is noticeably darker, much more muted than Lens Flare Glow.

Can I use Septic Green instead of Lens Flare Glow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 35). Septic Green is noticeably darker, much more muted than Lens Flare Glow.

Can I use Lens Flare Glow instead of Septic Green?

The same difference applies the other way round: Lens Flare Glow 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.