I don't see what so many people are mad about.
First you were mad that her real appearance is different than the concept art, and you liked the blue better.
Irelia is from Ionia, which is based at least partly on Japan. In Japan, the color red is sacred. Thus it makes sense that Irelia would wear red rather than blue, much like Ionia Master Yi having a red outfit.
I do agree that the real Irelia shouldn't be smiling, but that could easily be fixed with a custom skin, I'm sure.
As for actual gameplay as Irelia, I'm actually happy with how she's played. I at first expected her ult to be a skillshot, and since it isn't I'm somewhat relieved. I also don't see why people are mad about hiten style. It's built in life-steal, big deal. She isn't the only champion that gains extra damage from an ability, either. Yi's Wuju Style gives a similar buff, although it isn't true damage.
Overall I like her, and I plan on playing her even if you raging idiots get her nerfed to a single pinprick of base AD. Why? Because I think she looks cool, and will be fun to play.