Poseidon

Poseidon reminds me of the blue you see under office lights when the ocean is calm. It's a medium-deep blue, but it doesn't read as greenish or near-black like some of the darker neighbors. Compared to Capital Blue, Poseidon keeps a cleaner, cooler direction and feels less muddied. Versus Lost in Space, it's more saturated and more "ink" than "night-sky softened," so it holds its edge instead of smoothing out.

I reach for Poseidon when I want a primary that feels steady in motion: banking interfaces, healthcare apps, and data dashboards where the UI needs to look trustworthy without turning clinical. It's strong for persistent navigation, key metrics, and active states because the shade stays present without the extra softness you can get from Lost in Space. It also behaves more directly than Maniac Mansion, which leans slightly more assertive on very cool gray scaffolding.

Quick quirk: on very warm off-whites it can look a bit heavier than you'd expect, so I usually pair it with crisp whites or neutral grays and let it carry the hierarchy.