ΔE 26.9, loose: different enough that you should pick on purpose. Titan Mars Pale is noticeably lighter, more muted, warmer than Princess Pink. They are different kinds of paint: Army Painter Princess Pink is a one-coat contrast-style paint and Golden Titan Mars Pale is an opaque base/layer paint, 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 27). Titan Mars Pale is noticeably lighter, more muted, warmer than Princess Pink. They are different kinds of paint.
The same difference applies the other way round: Princess Pink is noticeably darker, more saturated, cooler.
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 Princess Pink on the colour wheel See Titan Mars Pale on the colour wheel
All matches: Princess Pink equivalents · Titan Mars Pale equivalents