Hexed Violet vs Violet Grey

How close are they?

ΔE 17.2, loose: different enough that you should pick on purpose. Violet Grey is a little darker, more muted, cooler than Hexed Violet.

Can I use Violet Grey instead of Hexed Violet?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 17). Violet Grey is a little darker, more muted, cooler than Hexed Violet.

Can I use Hexed Violet instead of Violet Grey?

The same difference applies the other way round: Hexed Violet is a little lighter, more saturated, warmer.

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.