A generator that paints one colour throws nothing and draws a valid image; the only symptom is a swatch that looks like the Solid pattern. This renders each generator at both the sizes the editor uses, across seeds and the corners of the slider space, and fails on a single colour or on one colour holding more than 97% of the pixels. It is what found the Cyclic automaton and Weathered cases. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>