Paul Kozlovskis wrote:
As a personal feeling, I believe mudansha (if training elsewhere) should follow the general guidelines of the dojo they visit. If only their yudansha wear hakama, it's probably best that you don't etc.
I've seen udansha kick visiting mudansha off the mat to remove their hakama in order to conform to the local standard. So the above is probably more than just good advice, it's sometimes the rules.
oh yeah, the two asu dojo i've studied at: white and black, hakama when the cho thinks you're ready (apocryphally when your ukemi is good enough that a half blind visiting sensei can see the skirt and call you for uke and not have to worry if you can take a fall).