Mule

Mule looks like a gray that got gently sun-bleached: soft and steady, but not washed out. Compared to Gotham, it's a step more relaxed and less confident, and it doesn't have that warm backbone. Next to Hurricane and Moon Rock, Mule reads a touch duller and more grounded, with less of the dusty cool feel and less of the taupe drift.

I use Mule when I want separation without making the UI feel heavy or overly cool. It's a strong backdrop for admin surfaces, ticketing systems, and dense workflow screens in SaaS where rows need to stay readable for hours. It also works well for editorial product pages and internal documentation layouts, especially when you want a neutral field that still feels finished, the one you reach for when you don't want the gray to announce itself. Pair it with charcoal text and slightly cleaner borders to keep hierarchy crisp, and it plays nicest with muted blues and subdued greens over punchy ambers.