Blue. My favourite place has always been the beach, and one day I hope I get to go to a beautiful beach with white sand and a vibrant blue ocean and sky. That would be my answer to typical colour questions, but in terms of the things you mentioned...
My "dress sense" has been almost non-existent for the past several years. I usually wear a combination of black and navy blue. In the distant past I wore various colours. For accessories it varies. As for home decor, I'm a bit weird with that. My living room (with a sofa bed so I can treat it as a bedroom) has two lime green walls and two silver grey walls, which is an odd choice (not sure how I came up with it) but I like it. I suppose I've made other colour choices based on the walls. I chose a white Ikea bookcase to place in front of one of the grey walls.
In my "cinema room" there's three dark(ish) red walls and a silver grey wall, arranged a little like a cinema if you can imagine it. I used a special paint for this grey wall since it was designed to work well with a projector. I ended up using a motorised projector screen anyway.

It really does look like you've just walked into a mini cinema with the black reclining sofa. (It wasn't cheap, but I guess you really do get what you pay for since it's just as comfortable and works just as well nearly three years later.)
You remind me of one of my sisters. For some time she was obsessed with black/white decor themes, although probably without as much colour as you described!