Doomfire Magenta vs Velvet Red

How close are they?

ΔE 41.9, loose: different enough that you should pick on purpose. Velvet Red is noticeably darker, much more muted, warmer than Doomfire Magenta.

Can I use Velvet Red instead of Doomfire Magenta?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 42). Velvet Red is noticeably darker, much more muted, warmer than Doomfire Magenta.

Can I use Doomfire Magenta instead of Velvet Red?

The same difference applies the other way round: Doomfire Magenta is noticeably lighter, much 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.