Nuclear Sunrise vs Flesh Tearers Red

How close are they?

ΔE 28.0, loose: different enough that you should pick on purpose. Flesh Tearers Red is noticeably darker, more muted, cooler than Nuclear Sunrise.

Can I use Flesh Tearers Red instead of Nuclear Sunrise?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 28). Flesh Tearers Red is noticeably darker, more muted, cooler than Nuclear Sunrise.

Can I use Nuclear Sunrise instead of Flesh Tearers Red?

The same difference applies the other way round: Nuclear Sunrise is noticeably lighter, 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.