On a really hot day, when only the most die hard among us would be wearing a suit in the first place, I like a yellow tie. A grey striped suit and white shirt, a business dress combination second in staidness only to navy blue with white, gets placed firmly in July with the simple addition of a yellow tie in a small neat pattern.
I've said it before, so forgive me if I'm beating a dead horse. Yellow ties are a tough nut, but they're great when you hit it right. Grey suits and navy blazers work perfectly, but keep them away from navy suits at all costs. An inexplicable but deep rooted unreasonable bias leads to me to find the navy suit/yellow tie combination unforgivably amateur. We've discussed this before.
True, a yellow tie, even more so a yellow bow tie, is not appropriate for many situations in which a grey striped suit is de riguer. Keep it out of the boardroom, unless you own the company. Keep it out of lower jobs, unless your father owns the company.
But if you're wearing the suit for your own pleasure, and not from requirement, go for it. I wore this simply to visit the city for lunch with a friend before working a night shift at the wine shop. The fact that my job, or any other part of my life, requires merely that I be clothed in anything at all means I did it for my own pleasure. The fact that it was over 90 degrees with near 100% humidity proves that I am clearly disturbed, and you'd do well not to take my advice anyway.