Metallic Red vs Crimson Magenta

How close are they?

ΔE 42.1, loose: different enough that you should pick on purpose. Crimson Magenta is noticeably lighter, much more muted, cooler than Metallic Red.

Can I use Crimson Magenta instead of Metallic Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 42). Crimson Magenta is noticeably lighter, much more muted, cooler than Metallic Red.

Can I use Metallic Red instead of Crimson Magenta?

The same difference applies the other way round: Metallic Red is noticeably darker, 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.