Is there a script to change layer colors within the layers palette in illustrator CS5?

If you have a doc open then you can do this… It will look for a layer by name but you can change that to index or whatever…

#target illustrator
var doc = app.activeDocument;
var lay, layCol;
try {
          lay = doc.layers.getByName( 'Copy' );
          layCol = new RGBColor();
          layCol.red = 255;
          layCol.green = 0;
          layCol.blue = 255;
          lay.color = layCol
} catch (e) {};