Subject: Is there a way to produce a blue electron beam

This time i will try to be more specific.I was thinking about making a 
lightsaber that would not be dangerous,should be visibile in day light, and 
should be able to repeal another of the same design.So is there any way to make 
a beam of electrons with a e/gun and give it some coulour ,like blue,or 
green  , and then contain it in a magnetic bottle to be long 1m(36 inch).

Re: Is there a way to produce a blue electron beam