Several years ago I started my ballet training as an adult. I phoned a studio to inquire about taking ballet. The instructor was very positive minded and encouraged me to start taking lessons. One of the first question that I asked was what were the studio's requirement regarding dance wear. My instructor informed me that the studio perferred all of its students male and female to wear leotards and tights. The only color requirement is that both the leotard and tights be of a solid color such as white, black, blue, pink or red. My first class I wore the traditinal black leotard with matching tights. I had no problem buying them at a local dance wear  store. The first few minutes of the class I felt a little awkard but by the end of the class I felt very comfortable. My instructor complemented me on wearing the proper attire to class. Once I wore a white unitard with a black dance belt by mistake.Noone made any comment to me about the attire. If you are serious about ballet the importance thing is to be comfortable. My class is mostly women and they seem to be very comfortable with me in the class with proper dance attire. I have tried wearing a t-shirt with tights but really find the leotard much more accomadating to the dance class. Yes I do have a pair of pink tightd that I some times wear with a black leotard. No body really cares.