ΔE 25.9, loose: different enough that you should pick on purpose. Amethyst is much more muted, cooler than Power Node Glow.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 26). Amethyst is much more muted, cooler than Power Node Glow.
The same difference applies the other way round: Power Node Glow is much 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.
See Power Node Glow on the colour wheel See Amethyst on the colour wheel
All matches: Power Node Glow equivalents · Amethyst equivalents