Tom is right. In most adult classes the dress code is not strict. Just as long as you're not wearing stripes that make the teacher dizzy, most men are prized
If you're a serious hard-worker, you'll find that many serious teachers prefer men to wear lighter colors so the muscles are easily observed.
If you're younger and in a graded class system, the uniform is usually more strict. But in graded class systems the male usually starts in black tights, white T-shirt, but as you move up, the tights get lighter, you move to white ballet slippers.
The really funny thing is that once you finish the grades and get into a company, almost anything goes. And the demands of company rehersals often see dancers in heavy warm-ups.
So "traditional" schools like the English RAD and many Russian schools have strict dress codes. In Cecchetti the exams have strict dress codes. But in many (most) adult classes you'll find in the US are wide open and more happy to have a guy in class that they don't care if you wear bike shorts, sweat pants, etc.
balletboy[/i]