ΔE 11.1, fair: the same colour family, but not a straight swap. Wrack White is more muted than Hobgoblin Hue.
Can I use Wrack White instead of Hobgoblin Hue?
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 11). Wrack White is more muted than Hobgoblin Hue.
Can I use Hobgoblin Hue instead of Wrack White?
The same difference applies the other way round: Hobgoblin Hue is more saturated.
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.