Transparent Red vs Ink Magenta

How close are they?

ΔE 44.6, loose: different enough that you should pick on purpose. Ink Magenta is a little darker, much more muted, cooler than Transparent Red.

Can I use Ink Magenta instead of Transparent Red?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 45). Ink Magenta is a little darker, much more muted, cooler than Transparent Red.

Can I use Transparent Red instead of Ink Magenta?

The same difference applies the other way round: Transparent Red is a little lighter, 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.