In Deadman Wonderland, is the Red Man is supposed to be Ganta's childhood hero, Ace Man? I watched Deadman Wonderland about two months ago, when I started I watched the first episode on Adult Swim. I saw the Red Man kill Ganta's classmates and other episode Shiro was passed out in dark basement with this older gentle man. 

As soon Shiro wake up it wasn’t her, she was a different person and she grabs this outfit that look like the Red Man’s clothes. Later on of the season it was Ganta’s flashback he had a figure look like Red Man also.    

Who is the red man? Aceman ? Shiro?
On the contrary to what Zeor mentioned, I believe that the Ace Man action figure did have some influence on the Wretched Egg and Shiro.

Spoilers


   At 1 minute into Episode 8 of the anime, we see that Shiro dropped down from the ceiling and attacked Azuma Genkaku, and then went on to point out her special move, which is identified to be Ace Man's special move: Ultra Chaos Endorphin Screw, Hadouken-Style Alpha-Wave Version Kick. Then she said, "Ace Man is here."

 When Shiro and Ginta were younger and were living together, Shiro would impersonate Ace Man (as seen in Episode 7 at 10:45). In that scene, Shiro also dropped down onto a dog and said, "Ace Man is on the scene."


In this sense, we can see that it's not simply coincidence that the Wretched Egg looked like Ace Man. The outfit most likely derives from Shiro's personality and her attachment to impersonating Ace Man for Ganta.

Conclusion

Ace Man is the action TV hero Ganta looked up to. Shiro is the Red Man, AKA Wretched Egg, or more precisely, the Wretched Egg is a split personality of Shiro's. The outfit of the Wretched Egg is derived from Shiro's personality where Shiro impersonates Ace Man to act as Ganta's hero.

So yes, Ace Man did have direct correlation to Shiro and the Wretched Egg.