It may sound obvious, but do consider that if you are colorblind, your options in the USN are very limited. You will not be able to drive ships or subs or fly (pilot or NFO). You can't be a SEAL.
You must go USMC ground (non-aviation) or choose a USN restricted line/staff position (e.g., supply, intel, aviation maintenance, etc.). Within the restricted line/staff corps, slots for each specialty are limited, so don't assume that you automatically can choose a particular one (e.g., intel) if you want it. It will depend on your class rank and other factors among those who must select those specialties. As a restricted line/staff corps officer, you are not eligible for command at sea, although you could eventually command shore installations. You may still go to sea, however.
I don't mean to discourage you, but ensure you consider why you wanted to go to USNA in the first place and whether you still can achieve those dreams if your service selection is limited. I believe there are more career options out of USAFA and USMA -- and maybe a greater likelihood of being admitted to their SAs -- with colorblindness, so you may want to look into those.
I suspect (but am not certain) that, due to the almost exclusive sea-going nature of USCG, colorblindness wouldn't be permitted but, you'd need to check with someone more familiar with that service. No clue re USMMA.