For the in boat speakers its not difficult at all -
Here are pics of the old-school SX65s (excuse the dirty floor, middle of the install)
Those are 3/4" thick rings behind the speakers and SMD LED strips around the tweeters inside the grilles.
Here's a Big12 with a 3/8" thick ring and green LEDs - I still need to make the faceplate, this was just to get it up and running in my buddies LSV;