ΔE 11.1, fair: the same colour family, but not a straight swap. Mephiston Red is a little darker, cooler than Matt Red.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Mephiston Red is a little darker, cooler than Matt Red.
The same difference applies the other way round: Matt Red is a little lighter, 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 Matt Red on the colour wheel See Mephiston Red on the colour wheel
All matches: Matt Red equivalents · Mephiston Red equivalents