wearing all black is gonna bring attention to you, unless you live in a rural area wher you have some woodland areas to cut across and such. but seriously, what is all black around you that lts you blend into the shadows, except for shadows. but then the only place you will be able to hide... are shadows, which is dark anyways which means no matter what your wearing you will most likely appear black anyways., bricks are red, cement cinder blocks are grey, street lights will illuminate everything around you and you will be a huge black blob.
i would suggest dark greys and splotches or rust brown, brick red, some black and maybe even blue and green. I think these are the most common colors you find in a city area. A few black stripes to break up your general body shape. It is much easier to see an object of a single color that it is to put together smaller shapes of different colors to get an entire image, spatial imagery i think its called.
As for stealthyness running through stuff, hiding behind things, this brings attention to you. hide in plain sight. like the guy 2 up from this post said, ninjas wore peasant clothing, farmer clothing and such so they can get near their victims and CUT THEIR F'KIN HEADS OFF!!!. too much??
And IMO, stealth like you see in the movies is for the movies, unless you are a parkour master thats gonna jump rooftop to rooftop jumping down 15ft dropoffs there is no way you you can reasonable be invisable and chase badguys around town. unless you wear a costume, just wear common street clothing. Get a reversable jacket, blue jeans, a few different colored hats if you plan on stalking people that think your following them... i mean "Follow" people.
thats my 62 cents on the matter.