ΔE 14.6, fair: the same colour family, but not a straight swap. Amethyst Purple is a little lighter, cooler than Pearl Light Red. They are different kinds of paint: Tamiya Pearl Light Red is a pearl paint and Vallejo Amethyst Purple is a metallic, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Amethyst Purple is a little lighter, cooler than Pearl Light Red. They are different kinds of paint.
The same difference applies the other way round: Pearl Light Red is a little darker, 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.
See Pearl Light Red on the colour wheel See Amethyst Purple on the colour wheel
All matches: Pearl Light Red equivalents · Amethyst Purple equivalents