Nightfall

Nightfall looks like a late-day shadow caught under glass. It's a cooler gray that's not as light as Good Night!, so it doesn't go soft and airy. And compared to Abyssal and Fiord, it isn't as deep or steel-heavy, which keeps it from feeling like a deliberate wall color.

I use Nightfall for secondary surfaces in healthcare platforms and admin interfaces, especially where you want separation without turning the whole screen darker. It works well for form backgrounds, disabled states, and the quiet card layers in dashboards and finance apps where the UI needs structure but can't afford to feel weighty. The mood is restrained, more "managed" than "receding."

One quirk: because it sits in that middle ground between lighter panel grays and the darker containers, test it against your deepest background once you've decided your type weight. If your layout already uses Abyssal, Nightfall can feel redundant unless you keep the hierarchy tight.