it's very hard to work out who a person is sadly in my opinion. Really it can only be for the dreamer to decide and what they feel about them.
I think it seems like a positive thing.
this
link has some interesting ideas about dreams of sex with strangers. They are just ideas about it. other ideas, could show a future partner (premonition) or could be a spirit guide or he could just be a symbol in the dream and doesn't represent anyone literally.
I think this dreams meaning might be about emotions and not being 'trapped' in a relationship or a partnership. Sex with a stranger means no ties, no responsibilities, "no strings attached". it also is an uncertainty but you are not bound by anything. will you see them again or never see them again? there is a freedom here that you can do this in a dream where as you might be more restrained in real life.
the room was blue, blue is recommended for painting rooms with in colour therapy for calmness and tranquillity. I read in a colour book I have that blue can represent spirit guides, perhaps a clue to the person.
his eyes were brown and that can be so grounding as a colour. Think of the earth. perhaps he is down to earth.
the ocean? well water is always emotions for me. It depends on so many factors as a symbol. is it a calm ocean, is it rough? is there danger? if it is in the background near the house perhaps it is calming and relaxing.
my view is that the dream is about your emotions and you want someone with no boundaries or something tying you down. This might be because of heartbreak and you don't want to commit or it might be that in your dreams you have your desires playing out. You wouldn't do that in real life because of inhibitions. just my ideas but think if you get a feeling about him or go to bed and ask before sleeping if you can get a message about who he was. You could try to do a reading with tarot or oracles asking about this.