Each country has its own regulations: In UK Only on emergency vehicles; when the lights are not being used as a primary light source. For US and Canada yes, see the link.
Yes, and the headlights are red.
... As i know it, In every state in the U.s. A street legal motorcycles must have working turn signals, headlights, ect. so Yes.
All 50cc motorcycles and under
the low beams should turn on when the motorcycle is turned on
Halo headlights are illegal in Washington.
yes
Ultraviolet headlights are generally not legal in the US because they can cause glare and are deemed unsafe for other drivers on the road. The legal requirement for headlights in the US is to have lights that emit white or amber light.
No, but some motorcycles have this benefit. Rider has turn on headlights himself.
of course it is
it's an illegal to use a different colored headlights.
Ultraviolet
sure why not