ΔE 12.3, fair: the same colour family, but not a straight swap. Royal Cloak is a little lighter, more muted, cooler than Tree Ancient.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 12). Royal Cloak is a little lighter, more muted, cooler than Tree Ancient.
The same difference applies the other way round: Tree Ancient is a little darker, more saturated, 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 Tree Ancient on the colour wheel See Royal Cloak on the colour wheel
All matches: Tree Ancient equivalents · Royal Cloak equivalents