ΔE 9.3, close: similar, with a visible difference side by side. Midnight Blue is a little lighter than Black Tone. They are different kinds of paint: Army Painter Black Tone is a wash/shade and Reaper Midnight Blue is an opaque base/layer 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). Midnight Blue is a little lighter than Black Tone. They are different kinds of paint.
The same difference applies the other way round: Black Tone is a little darker.
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 Black Tone on the colour wheel See Midnight Blue on the colour wheel
All matches: Black Tone equivalents · Midnight Blue equivalents