Submodels: light up part of a fixture

All steps

1. Select the fixture
   A submodel is a named part of a fixture, like the star on top of this tree. Click the tree under Devices: Properties on the right shows its settings.
2. Add a submodel
   Under Submodels, click + to add one. It starts with a placeholder name and no pixels.
3. Name it
   Click the name and type what this part is, here Star on top. Press Return to keep it.
4. Choose its pixels
   Enter the pixel numbers that belong to it, as ranges and single numbers: the star is the last five LEDs of the chain, 46-50. The number next to the name counts them, and the submodel now shows up under the tree in Devices.
5. Select the submodel
   Click Star on top under Devices. Now effects target only the star; the Target bar below Devices shows it.
6. Run an effect only there
   Click Color Fade. It runs on the star alone and the rest of the tree stays dark. Hold ⌘ while clicking to target several submodels and fixtures at once.