Goddess Glow vs Demon Brown

How close are they?

ΔE 24.0, loose: different enough that you should pick on purpose. Demon Brown is noticeably darker, warmer than Goddess Glow.

Can I use Demon Brown instead of Goddess Glow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 24). Demon Brown is noticeably darker, warmer than Goddess Glow.

Can I use Goddess Glow instead of Demon Brown?

The same difference applies the other way round: Goddess Glow is noticeably lighter, cooler.

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.