This should be very close to what you are after. Make a copy of your existing lay file in the starcas directory, then put this lay file from the attachment into your starcas directory. Make sure MAME isn't running when you do this. If you want/need to adjust the strength of the colored overlay parts, look at line 33 for the value of the color alpha value. I set it to .05, which looks good on my monitor, but you may have to tweak it on your setup. The value goes from 0 to 1.
Default.lay