The black is fine, even Man of Steel have some black lining in his 1st costume. He looks slim in the suit and not bulky.
"Let them Hate as long as they Fear"

There is red ya know..
But they'll probably tinker with it as the film and films progress.
=w=

His costume sucks.too bulky, not sleek, and black?!?
Say, do you hear that? It's the sound of the Reaper..

Ok cool. Then Barry probably gets an upgrade towards the end of the movie. I thought it may be the new suit as headpiece looked different from the one in JL teaser trailer. It's probably the same just different lighting. This scene grab does look like it comes from the new trailer. Apparently we get a lot of Flash and Aquaman in it and we see Steppenwolf.

still looks like the one he made himself. and I say that because it's the same suit we see in SS.
=w=

Is it still an assumption Bruce just gives him a suit or is that confirmed knowledge. I can see him letting Barry into the lab to use waynetech