A living instrument that tunes toward truth. The needle converges on the true mark as you log real production, the tolerance window narrows, and it locks with a confident glow when it is dialed in to you.
Once it locks on true, a hairline micro-oscillation keeps the needle alive and the band glow breathes on a slow heartbeat. It is not decoration: it says the engine is still tuning itself against every fresh reading.
That is the moat, felt in one glance. A cheaper app gives you a generic curve. This one is visibly, continuously tuned to your panels, your shade, your wiring.
Every level is separable with zero hue information. Needle position (scattered → dead center), error-band width (full track → hairline), filled tick count (0/1/2/3 of three), lock-bracket shape (absent → closed brackets), the explicit text label, and a distinct motion signature (search → converge → breathe) all carry the state. Lime is reserved for the live, dialed-in tier as reinforcement, never as the sole signal. Flip Grayscale proof above to confirm it reads with all color removed.