White or Black

Crowe=Bad Denzel=Good (Note the octagonal and cross-quarter platform)

Crowe=Good Denzel=Bad

American Gangster attracts attention by having the primary black and white theme associated with the checkers most frequently seen in synchromystic works on the Masonic tracing boards. The posters of the film show Denzel (bad guy/gangster) and Crowe (good guy/cop) in primary black and white with a mirrored NY skyline. Thus the theme of duality and reversal is extremely prevalent. The movie itself often goes into the issue of race as Denzels status as a black Kingpin is uncharacteristic and the main players are of opposite colour (thus white vs. black)

Interesting to note the reversal expressed again in there earlier partnership 'Virtuosity' where Crowe plays the virtual villain while Denzel takes the cop role.

Thanks to Piepan for pointing this out.

For more info read Black or White