I see your "wouldn't it be confusing" and raise you a "would it be bad if it was confusing?"
Despite looking identical they're still pretty distinguishable. They have completely different personalities and different clothing. Being confused seems like a minor inconvenience really. Besides, having twin characters certainly isn't exclusive to KH. Most stories take advantage of the fact that there are multiple characters that look identical.
Practically this.
I know this may be a somewhat mean train of thought, but I often have the impression that people who complain about Roxas and Ven looking alike are just too lazy to take a closer look in order to differentiate them, which isn't even that difficult to begin with.
It's also interesting that Donald's nephews or Riku and Repliku (or Data-Riku) do not get this much of attention despite it being the exact same issue.
Indeed, KH is actually running on a common train there, as this "feat" of having two identical strangers is actually very common in fictional works, like in video games with Celes and Maria from FF VI, Tidus and Shuyin in FF X/FF X-2 or Luke and Asch from Tales of the Abyss.
Heck, very famous works like "The Great Dictator" from Charlie Chaplin or Mark Twain's "The Prince and the Pauper" (which has also a Disney version with Mickey in a double role) run on that premise alone.
A fair point I could also Roxas doing something thinking along those lines though him getting a haircut or getting a entire design change unlikely.
As mentioned there distinguishable as is though I wouldn't mind Roxas doing something to further set himself apart. Especially if the meeting goes the route Solosis mentioned with Roxas feeling down that even his face isnt really his own and does something to further assert himself as his own person.
Considering how easy it seems to work with Sora and Vanitas, that may possibly be the most feasible route to go if Roxas really gets some identity crap
again.
Maybe he can dye his hair red, causing Lea to complain that he isn't the only redhead anymore (or he actually likes it so much that he's over Roxas even more than before), or maybe black, in order to get that brother/sister imagery with Xion going.
Who knows, maybe they can even spin some bittersweet stuff with that like i.e. that a finally redeemed/freed Isa takes "a bullet" of sorts for Roxas since he wants Lea to be happy and knows he won't make it/feels unworthy to be Lea's friend anymore and Roxas later takes the opportunity to pay respect to Isa by giving his hair a blue color.
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That being said though, let's take a look at what sets them apart and what's actually identical between them:
Identical traits:
- same face (but that goes for Sora as well)
- same eye color (ditto for Sora)
- same body build (although in some artworks and images Ven comes over as a bit skinnier)
- same hair style and color.
Differences:
- shoes (Roxas: sneakers, Ventus: armored boots)
- pants (Roxas has pants going fully down, Ven shows some leg)
- upper clothes (Roxas has two jackets, Ventus a plain black shirt, a vest and a jacket)
- their wristbands (Roxas' has thin, black edges, Ven's has thick, white edges)
- eyebrows (Roxas: brown, Ventus: blonde)
- voice
- battle style (Roxas: Forward wielding + dual wield, Ventus: backhand wielding + shorter Keyblade)
So, all in all, like Solo said, the only time when there might really come up a definitive problem of differentiating them would be if we get a complete nude shot (and that won't happen due to ratings of the games, lol).