ΔE 21.5, loose: different enough that you should pick on purpose. Crimson Magenta is noticeably darker, much more saturated than Pearl Light Red. They are different kinds of paint: Tamiya Pearl Light Red is a pearl paint and Vallejo Crimson Magenta is a metallic, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Crimson Magenta is noticeably darker, much more saturated than Pearl Light Red. They are different kinds of paint.
The same difference applies the other way round: Pearl Light Red is noticeably lighter, much more muted.
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.
See Pearl Light Red on the colour wheel See Crimson Magenta on the colour wheel
All matches: Pearl Light Red equivalents · Crimson Magenta equivalents