Absolutely agree with Jess’s advice. During my schemes, I rotated between the only two suits I had (one navy and one mid-grey). That said, I definitely remember people wearing black suits and still making excellent impressions and securing training contracts. I've also been at firms where vacation schemers appeared to be dressed slightly more relaxed. For instance, I’ve seen men in suit pants/trousers with a button-up shirt and a nice sweater vest or half-zip jumper, and they looked completely appropriate. I'd be curious to know
@Jessica Booker's thought on this, but my impression has been that, as long as you look neat and professional, feel comfortable, and show that you’ve made an effort, that should be good enough as far as your wardrobe is concerned.
If you're concerned about the black suit, you could soften it with a lighter shirt or a subtle tie. Don’t let the lack of multiple suits stress you out. Good luck with your scheme