This is what a city looks like when it is being operated rather than photographed. Siemens' Element system supplies the ground — Deep Blue `#000028`, dark because a video wall has to stay readable across a dim room, not because dark looks futuristic. On it sits a Cesium 3D Tiles street model with utilities, traffic and predictive alarms as toggleable overlays.

Colour is rationed. Cyan `#00BEDC` is the data-visualisation highlight, bold-green marks live streams and healthy states, petrol fills inactive geometry, and everything else is navy panel surface and hairline. Glow appears only where something is genuinely emitting. Panels dock; they do not float.