Sparkling Amethyst vs Silver RLM01 (Met.)

How close are they?

ΔE 35.6, loose: different enough that you should pick on purpose. Silver RLM01 (Met.) is noticeably lighter, much more muted than Sparkling Amethyst.

Can I use Silver RLM01 (Met.) instead of Sparkling Amethyst?

Not as a straight swap; see the closer alternatives below. Loose match (ΔE 36). Silver RLM01 (Met.) is noticeably lighter, much more muted than Sparkling Amethyst.

Can I use Sparkling Amethyst instead of Silver RLM01 (Met.)?

The same difference applies the other way round: Sparkling Amethyst is noticeably darker, much 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.