The title says it all really! Valve made it so that tractor beams change colour depending on their direction. Is it possible for mappers to change the beams to be an arbitrary colour? I tried doing:

ent_fire my_tractor_beam color "255 0 0 255"

All that happened was that part of the tractor beam emitter model turned red. Then, after some investigating in the console I tried:

ent_fire projected_tractor_beam_entity color "255 0 0 255"

This didn't work either - though I was able to kill the beam entity in this way. Any other suggestions?

The Colour is hard coded, the particle's colour are too.

You could always edit the particles and thats it.