Gryph-Charger Grey vs Violet Hint

How close are they?

ΔE 22.7, loose: different enough that you should pick on purpose. Violet Hint is much more saturated, warmer than Gryph-Charger Grey.

Can I use Violet Hint instead of Gryph-Charger Grey?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 23). Violet Hint is much more saturated, warmer than Gryph-Charger Grey.

Can I use Gryph-Charger Grey instead of Violet Hint?

The same difference applies the other way round: Gryph-Charger Grey is much more muted, 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.