ΔE 16.4, loose: different enough that you should pick on purpose. Azurite Hue is noticeably darker, warmer than Frostheart. They are different kinds of paint: Citadel Frostheart is a one-coat contrast-style paint and Golden Azurite Hue is an opaque base/layer paint, so they won’t behave the same on the model even where the colour is close.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Azurite Hue is noticeably darker, warmer than Frostheart. They are different kinds of paint.
The same difference applies the other way round: Frostheart is noticeably lighter, cooler.
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 Frostheart on the colour wheel See Azurite Hue on the colour wheel
All matches: Frostheart equivalents · Azurite Hue equivalents