For a standard Army Blackhawk, the correct color is Helo Drab Green. The only black Blackhawks are Special Ops MH-60Ls used by the Army's 160th SOAR (Spec Ops Aviation Regiment). The Academy AH-60L DAP (actually an MH-60L, The US Military doesn't use the AH designation with Blackhawks) depicts one of these. The gray ones you saw were most likely either USN Seahawks or USAF Pavehawks.
The seats can be a little tricky. I built them by first putting the roof support bar for the seats in place, then I constructed the cabin. I built the seats completely, to include the lower support legs at their 45 degree angles. I then inserted each seat through the side of the cabin and first attached the upper points, then attached the lower support legs in their holes on the floor. I did this after all the parts were painted adn used a little superglue to secure them all in place. Hope that helps.
You can see how mine (UH-60L and MH-60L DAP, among other helos) turned out at my Showcase II below. Check here for a write-up of the build.
Gino P. Quintiliani - Field Artillery - The KING of BATTLE!!!
Check out my Gallery: https://app.photobucket.com/u/HeavyArty
"People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf." -- George Orwell