People are really kind of dumb when it comes to that. Izzy and Luna both have pink harnesses, Izzy's has purple hearts on it, with a purple leash. She can even have a PINK DRESS on and people will still ask if she's a boy or girl
I'm sure the light blue will be very pretty on your baby so who cares what others have to say. I'm sure there will be some dingbat who assumes she's a boy, but the heck with them