uThe worst thing you can do in Japan job interviews is to stand out or appear different. v
That's a bit of an exaggeration. If standing out/appearing different were an immediate deal-breaker, foreigners would be essentially unable to get jobs in Japan, since, by percentage, we're almost always going to stand out from Japanese candidates.
On the other hand, it's often a bad idea, in a job interview in Japan, to be seen as actively, purposely trying to appear different, which is a separate thing from simply being different. I've got blond hair, and that hasn't prevented me from getting jobs in Japan, even though it's a color that definitely stands out in Japanese workplaces. However, if I had, say, green hair, which I'd dyed as part of a deliberate effort to stand out, then yes, that would probably have lost e a few job offers along the way for office jobs.
With something like suit color, that gets amplified. If I wanted to buy a navy, gray, or black suit in Japan, I could walk 5 minutes from any major train station in downtown Tokyo and find multiple stores stocked with dozens of styles for each of those colors. On the other hand, if I wanted to buy a white suit, I'd probably have to special order it, and maybe go to a specific specialty shop. In other words, I'd have to put a lot of extra effort into getting a white suit in Japan, which would be seen as a sign that I'm actively trying to stand out.
But again, that's not to say Japanese companies want to hire mediocre, average workers. If you excel in some skill or have extra knowledge that's related to the work you're going to be doing, that's an advantage over other candidates, even though it's something that makes you "different."
Japanese companies highly value the ability to work as part of a team. In general, if they're hiring someone new, their primary concern is whether or not the candidate can help the company and its existing employees. But by doing something deliberately to stand out in a non-work performance related way shifts the narrative from "Here's what our company needs, and do you have those skills/traits?" to "Hey, look at how stylish I think I am!" As mentioned above, for some jobs/industries, like cutting-edge apparel marketing or entertainment promotion, a "cool" image might be a plus, or even a requirement. But for a regular office job? No one cares if you can pick out a cool suit, so showing off that talent can make them feel like maybe you're not really all that interested in talking about, or eventually doing, the job you're interviewing for.