ΔE 5.2, very close: most people won’t see a difference side by side. Transparent Blue is a little darker than Ultramarine Blue. They are different kinds of paint: Army Painter Ultramarine Blue is an opaque base/layer paint and Green Stuff World Transparent Blue is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Yes, for most jobs. Very close match (ΔE 5). Transparent Blue is a little darker than Ultramarine Blue. They are different kinds of paint.
The same difference applies the other way round: Ultramarine Blue is a little 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 Ultramarine Blue on the colour wheel See Transparent Blue on the colour wheel
All matches: Ultramarine Blue equivalents · Transparent Blue equivalents