Darken This (UI Highlighting)

// Darkens the selected layer by adding an adjustment layer
// with a Levels effect to reduce brightness.
// Ensure a layer is selected before applying the effect.
if (app.project.activeItem.selectedLayers.length > 0) {
  // Get the selected layer
  var selectedLayer = app.project.activeItem.selectedLayers[0];
  // Get the index of the selected layer
  var layerIndex = selectedLayer.index;
  // Create an adjustment layer
  var adjustmentLayer = app.project.activeItem.layers.addSolid(
    [1, 1, 1],
    "Adjustment Layer",
    app.project.activeItem.width,
    app.project.activeItem.height,
    1
  );
  adjustmentLayer.adjustmentLayer = true;
  // Set the in and out points of the adjustment layer to match the selected layer
  adjustmentLayer.inPoint = selectedLayer.inPoint;
  adjustmentLayer.outPoint = selectedLayer.outPoint;
  // Set the label color of the adjustment layer to Lavender
  adjustmentLayer.label = 10;
  // Add a Levels effect and set the output white to 130
  var levelsEffect = adjustmentLayer.Effects.addProperty("ADBE Pro Levels2");
  levelsEffect.property("Output White").setValue(130 / 255);
  // Move the adjustment layer to the correct position in the layer stack
  adjustmentLayer.moveBefore(app.project.activeItem.layer(layerIndex + 1));
} else {
  alert("Please select a layer first.");
}
// Script created by Jack Vaughan (jackvaughan.com/tools)