Dragon Red vs Dark Magenta

How close are they?

ΔE 16.4, loose: different enough that you should pick on purpose. Dark Magenta is noticeably lighter, more muted, cooler than Dragon Red.

Can I use Dark Magenta instead of Dragon Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Dark Magenta is noticeably lighter, more muted, cooler than Dragon Red.

Can I use Dragon Red instead of Dark Magenta?

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