Luxion Purple vs Replenish Blue

How close are they?

ΔE 21.4, loose: different enough that you should pick on purpose. Replenish Blue is a little darker, cooler than Luxion Purple.

Can I use Replenish Blue instead of Luxion Purple?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 21). Replenish Blue is a little darker, cooler than Luxion Purple.

Can I use Luxion Purple instead of Replenish Blue?

The same difference applies the other way round: Luxion Purple is a little lighter, 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.