I believe USNA told us that up to 2% (~20 mids) of the class can receive a waiver for color-blindness each year. If I recall correctly, you must sign something on I-Day (or before) stating that you will go USMC. I haven't heard about being able to go Restricted Line. My guess -- and it's only that -- is that Restricted Line is an option for those NPQ for USMC or who, for some other reason, aren't able to go/aren't selected for USMC. You cannot be a pilot, NFO, SWO or submariner with colorblindness -- or so they said.
There may be more options at the other SAs, especially USMA, so you might explore that.