Wrack White vs Gypsum White

How close are they?

ΔE 13.2, fair: the same colour family, but not a straight swap. Gypsum White is noticeably darker than Wrack White.

Can I use Gypsum White instead of Wrack White?

Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 13). Gypsum White is noticeably darker than Wrack White.

Can I use Wrack White instead of Gypsum White?

The same difference applies the other way round: Wrack White is noticeably lighter.

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.