Petrol Slumber

Petrol Slumber looks like the surface of a calm, dark pool under shop lights. It's a gray, but it carries a muted blue-green undertone that keeps it from feeling like the warmer drift you get from Cinder. Compared to Black Pearl, it's less icy and less flat-black, and it has a softer depth that won't read as a hard, screen-like wall.

I use this when I want dark mode UI chrome to feel present but not assertive. It's great for video editors and streaming dashboards where panels need separation without turning sterile. It also works well in dashboards and finance apps that want contrast, but don't need the sharper, almost neutral punch of Nightmare Fuel.

Pair it with cool light type and restrained accent colors; if your hierarchy is fuzzy, this shade's calm undertone can make everything feel uniformly "dark" instead of layered.