ΔE 9.4, close: similar, with a visible difference side by side. Transparent Sepia is a little darker, cooler than XV-88. They are different kinds of paint: Citadel XV-88 is an opaque base/layer paint and Green Stuff World Transparent Sepia is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Transparent Sepia is a little darker, cooler than XV-88. They are different kinds of paint.
The same difference applies the other way round: XV-88 is a little lighter, 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 XV-88 on the colour wheel See Transparent Sepia on the colour wheel
All matches: XV-88 equivalents · Transparent Sepia equivalents