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.
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.
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.