Is it possible to loop through items/layers and change the color overlay?

Is it possible to loop through items/layers and change the color overlay? I can get select layers but am unsure how to loop through and change the color overlay.

I am using

app.executeCommand(app.findMenuCommandId("Color Overlay"));

overlay.layerStyle.colorOverlay.color.setValue(10);

to change other properties but on Overlay it simply fails.