ΔE 13.9, fair: the same colour family, but not a straight swap. Dark Reaper is a little darker, more saturated than Ultimate Cup of Coffee.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Dark Reaper is a little darker, more saturated than Ultimate Cup of Coffee.
The same difference applies the other way round: Ultimate Cup of Coffee is a little lighter, 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 Ultimate Cup of Coffee on the colour wheel See Dark Reaper on the colour wheel
All matches: Ultimate Cup of Coffee equivalents · Dark Reaper equivalents