In Apollo Justice: Ace Attorney, Apollo never notices the uncanny resemblance between the picture on the wall at the Wright and Co Offices and the victim of his first case (not even noting familiarity) even when the only difference is a goatee. On the other hand, Phoenix notices from the first meeting. The player, on the other hand, stands a chance of noticing at first glance, even without color.
Earlier in the same series, Furio Tigre disguises himself as Phoenix Wright in order to frame someone for murder. This 'disguise' consists of a suit, a fake attorney's badge (made of cardboard!) and loudly proclaiming himself to be Phoenix Wright. It works despite every major player in the case knowing Phoenix personally. Because they have the same hairstyle. ... Furio Tigre is huge and orange. Gumshoe mentions that many people on the court had "big question marks on their heads" when Not Phoenix made his apparition, but every time someone tried to point this out, Furio literally roared them into silence. Even more bizarrely, the disguise is apparently good enough to fool the player — the first you see of Furio Tigre is in the chapter intro where Phoenix Wright loses a case... and he's rendered as completely indistinguishable from the real Phoenix.
Trials and Tribulations subverts this with Dahlia Hawthorne when she appears to turn up in "Bridge to the Turnabout" with a different hair colour and nun's garments (retaining the same hairstyle and mannerisms, thus the Paper-Thin Disguise). The subversion? It's actually her twin sister.
Trials and Tribulations, the one difference between Godot and Diego Armando is basically a pallet swap and a face visor.
Chris in Princess Waltz. How obvious is it? Before The Reveal, knowing how bad a job she's doing acting, Chris asks in a roundabout way if Arata is sure he doesn't suspect her of anything. And barely refrains from mentioning what: Being a girl. It gets worse. He walks in on her with no disguise (bath) and still doesn't get it. All the yaoi fangirls in the class squee....
Little Busters! has Mask the Saito, a mysterious masked man that appears and starts challenging people if, after being returned to the bottom of the battle rankings early on, you can make you way up to the top again. At first glance, it isn't obvious who it is, but as soon as he starts talking it's very clearly Kyousuke's voice. If you lose to him, he doesn't even bother to keep up the charade, turning around and walking off (revealing distinctive red/brown hair) while throwing the mask away. Riki is faintly bemused by the entire thing, but plays along.