- effect.pickColor {effect, param|prop, x, y (layer px), average?}: the colour of the effect's
input at a point, set on the parameter (one undo step). Keying effects' Effect Controls
eyedroppers use it, since the shown frame is already keyed; Ctrl/Cmd+click averages 5x5.
- effects::aliases / name_matches: Effects & Presets and effect.list (MCP list_effects) find
Key Light by After Effects' name ("Keylight (1.2)").
- End-to-end test: a green-screen plate with an uneven screen, spill and soft edges keyed via
effect.apply "Keylight (1.2)", pick, Clip Black / White and a render; UI eyedropper test.
- Docs: parity, agents (green-screen recipe).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>