Warpstone Glow vs Goblin Flesh

How close are they?

ΔE 16.1, loose: different enough that you should pick on purpose. Goblin Flesh is noticeably lighter, more muted, warmer than Warpstone Glow.

Can I use Goblin Flesh instead of Warpstone Glow?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Goblin Flesh is noticeably lighter, more muted, warmer than Warpstone Glow.

Can I use Warpstone Glow instead of Goblin Flesh?

The same difference applies the other way round: Warpstone Glow is noticeably darker, more saturated, 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.