ΔE 14.7, fair: the same colour family, but not a straight swap. Old Rose is noticeably darker, more saturated, cooler than Porcelain Rose.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 15). Old Rose is noticeably darker, more saturated, cooler than Porcelain Rose.
The same difference applies the other way round: Porcelain Rose is noticeably 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 Porcelain Rose on the colour wheel See Old Rose on the colour wheel
All matches: Porcelain Rose equivalents · Old Rose equivalents