Subject: what wavelenght is the light generated by cerenkov effect?

I know that cerenkov light is generated in materials by particles 
travelling faster than the speed of light in this material. However nobody 
has been able so far to tell me in what precise color is this light. 
everything I could find is that it is sometimes said to belong to the blue 
or even the whole visible spectrum and sometimes to the UV region. Having a 
precise answer could help me in my ph-D where I would like to get rid of 
Cerenkov light generated in plastic optical fiber by filtering it...
thanks a lot if you can help.
fred

Re: what wavelenght is the light generated by cerenkov effect?