ΔE 9.1, close: similar, with a visible difference side by side. Black Red is a little lighter, more saturated, cooler than Mahogany Brown.
Usually, if you are not matching paint already on the model. Close match (ΔE 9). Black Red is a little lighter, more saturated, cooler than Mahogany Brown.
The same difference applies the other way round: Mahogany Brown is a little darker, more muted, 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 Mahogany Brown on the colour wheel See Black Red on the colour wheel
All matches: Mahogany Brown equivalents · Black Red equivalents