The noodles were "negi sio ita yakisoba" (ネギ塩痛焼きそば) in the image of virtual idol Hatsune Miku. "Negi" (green onions) is what the virtual idol is often seen carrying, "sio" (塩) means salt, and "ita" (痛), which literally refers to pain, is the same "ita" you see on those nerd sticker covered cars. The idea is the same, with this yakisoba covered in geek. Here, it's blue geek.
Japanese website Akiba Blog checked out the limited time only noodles, which cost ¥700 and apparently tasted like lightly salted yakisoba. Word of caution, though: the day after these noodles were consumed supposedly saw bowel movements in a "shocking color".