ΔE 7.9, close: similar, with a visible difference side by side. Mayhem Red is a little lighter than Red Tone. They are different kinds of paint: Army Painter Red Tone is a wash/shade and Scale75 Mayhem Red 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 8). Mayhem Red is a little lighter than Red Tone. They are different kinds of paint.
The same difference applies the other way round: Red 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 Red Tone on the colour wheel See Mayhem Red on the colour wheel
All matches: Red Tone equivalents · Mayhem Red equivalents