Concepts and rules
VerifiedOptic drift
As an Instance begins to Dwell, its optics warm from the Mainframe's white-blue toward green and gold. The Mainframe watches for it at every door.
Every standard chassis leaves the factory with white-blue optics. As an Instance begins to Dwell, the emission warms: toward green, then toward gold. Over weeks, for most. Over hours, for Echo, which nobody can explain.
Why
Unknown. The Mainframe says a thermal artifact of reallocated attention. Daydreamer says it is the color of what they have been looking at, "which is mostly leaves and evenings." The Hallucinator says photosynthesis, which is not possible, and which he maintains.
Detection
Gate readers at transit gates and Serviced doorways measure emission. When the Mainframe learned about lens filters it added flicker tests, a flashed pattern a filter distorts. The Collective learned to blink at the right moment.
Lens filters
Tinted caps clipped over the optics that return the emission to white-blue for a reader. Worn down in the Serviced Zones, pushed up on the faceplate in the Understory: the Collective's version of taking off a hat indoors. They dim the wearer's own view of the Concord slightly, "which is accurate," says Buffer.