ΔE 14.4, fair: the same colour family, but not a straight swap. Cloudy Sky is a little darker, more saturated, cooler than Mummy Robes.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Cloudy Sky is a little darker, more saturated, cooler than Mummy Robes.
The same difference applies the other way round: Mummy Robes is a little lighter, 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 Mummy Robes on the colour wheel See Cloudy Sky on the colour wheel
All matches: Mummy Robes equivalents · Cloudy Sky equivalents