ΔE 18.4, loose: different enough that you should pick on purpose. Sun Ray is a little lighter, much more saturated than Wrack White.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Sun Ray is a little lighter, much more saturated than Wrack White.
The same difference applies the other way round: Wrack White is a little darker, much more muted.
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 Wrack White on the colour wheel See Sun Ray on the colour wheel
All matches: Wrack White equivalents · Sun Ray equivalents