ΔE 14.1, fair: the same colour family, but not a straight swap. Ink Skin is noticeably darker than Targor Rageshade. They are different kinds of paint: Citadel Targor Rageshade is a wash/shade and Vallejo Ink Skin is an ink, glaze or transparent paint, 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 14). Ink Skin is noticeably darker than Targor Rageshade. They are different kinds of paint.
The same difference applies the other way round: Targor Rageshade is noticeably lighter.
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 Targor Rageshade on the colour wheel See Ink Skin on the colour wheel
All matches: Targor Rageshade equivalents · Ink Skin equivalents