Wow, I've been thinking about
colour names today:
Cyan,
Indigo,
Azure, Cobalt,
Carmine, Viridian.
Practically all of these names, including
Blue, appear to be unusable to me.
Blue is one of my favourite colours, and the sound is nice, but it's also unapologetically blunt and might have lots of unpleasant associations...
As for gender... I think, it leans towards girl names, but I can easily see it on a boy.