Sunpetal vs Septic Green

How close are they?

ΔE 36.0, loose: different enough that you should pick on purpose. Septic Green is noticeably darker, much more muted, cooler than Sunpetal.

Can I use Septic Green instead of Sunpetal?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 36). Septic Green is noticeably darker, much more muted, cooler than Sunpetal.

Can I use Sunpetal instead of Septic Green?

The same difference applies the other way round: Sunpetal is noticeably lighter, much more saturated, 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.