ΔE 7.5, close: similar, with a visible difference side by side. Transparent Blue is more saturated than Blue Tone. They are different kinds of paint: Army Painter Blue Tone is a wash/shade 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.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Transparent Blue is more saturated than Blue Tone. They are different kinds of paint.
The same difference applies the other way round: Blue Tone is more muted.
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 Blue Tone on the colour wheel See Transparent Blue on the colour wheel
All matches: Blue Tone equivalents · Transparent Blue equivalents