ΔE 13.8, fair: the same colour family, but not a straight swap. Phoenix Orange is a little lighter, more muted than Gryph-Hound Orange. They are different kinds of paint: Citadel Gryph-Hound Orange is a one-coat contrast-style paint and Green Stuff World Phoenix Orange is an ink, glaze or transparent paint, so they won’t behave the same on the model even where the colour is close.
Only where an exact match doesn’t matter, such as a new unit or a highlight. Fair match (ΔE 14). Phoenix Orange is a little lighter, more muted than Gryph-Hound Orange. They are different kinds of paint.
The same difference applies the other way round: Gryph-Hound Orange is a little 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 Gryph-Hound Orange on the colour wheel See Phoenix Orange on the colour wheel
All matches: Gryph-Hound Orange equivalents · Phoenix Orange equivalents