Photoshop scripting help

Hi,

I want a script that is going to load in a series of psd files, select certain layers and change the colours.

I can get the files loaded in and select the layer, but what I can’t find out how to do is to change the colour of the shape.

I have a button shape and I want to change it from green to blue, and I want the script to do this for me.

I also want it to be able to edit layer styles, so that I can tell it to use the foreground colour as a colour overlay and set the opacity of that.

Any help would be greatly appreciated.