Seen in the Crysis: Warhead HUD. What does that really mean?
Is Psycho's suit any different from Nomad's?

Do you mean the colour of the interface? Because you can change it in both games.
As far as I know it's the same suit.

I had totally forgot about my question. No, not the color. In the lower right corner it says Sykes Mod.
That's pretty much it. And as you said, both suits are identical so I seriously don't get why CryTek put it there.

Wait I made an mistake. Gameplay wise they're the same. But graphically they differ slightly. In warhead the nano suit is slightly more yellow.
It's possible they added a few words like Skykes, because that's also the name of the character you play in Crysis Warhead if I'm not mistaken.

I just realised this because I'm installing a old mod that makes the nano suit high res, it's called Ultra-Res Nanosuit and it has a configuration utility that let's you tweak your own suit. I can't find it on the internet atm, luckily it's still on my harddisk.