ΔE 17.2, loose: different enough that you should pick on purpose. Cold White is noticeably lighter, more muted than Ion Blue.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Cold White is noticeably lighter, more muted than Ion Blue.
The same difference applies the other way round: Ion Blue is noticeably darker, 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.
See Ion Blue on the colour wheel See Cold White on the colour wheel
All matches: Ion Blue equivalents · Cold White equivalents