I don't buy the conservative argument in Canada. I see it made on SDN, but here there are so many med students with coloured hair, gauged ears, etc. etc. I seriously doubt it's much of a risk at all.
I'm a current male med student with various aesthetic choices that are not conservative, and I've never had a staff say anything or glower at me because of it. Gotten along just fine with elderly, fussy doctors, got good evals from them, really no issues.
If you're dressed professionally, there's really such a minimal chance that they think anything but "Oh that's what the kids are doing now" and move on