Those beams don't look right to me at all - far too dull. If you have white cores then they should be at maximum brightness. The idea of the originals, to me, is that the light from the core of the beam is so bright that the eye (or cockpit display) can only see it as blindingly white. The falloff corona looks red or green or whatever because the energy level isn't as high on the outer edges of the beam and so doesn't blind you.
...Own comments:
-the shivan-beam texture seems to suffer from lack of brightness in-game.
-the tile factors still need to be adjusted - currently they are a bit too small, I reckon.
-I suppose the violet appearance of that AAA beam is mostly because of the red haze in the screen.
-Whenever a beam equipped with these textures hits something, the texture stops too abruptly and destroys the illusion of a round bar of energy, if you look too carefully.
I agree, the core brightness problem was and is most prominant in the Shivan Beam, but it was to some extent a problem to other beams as well.
To me it looks like for some reason, there would still be transparency even in the middle of the beam texture's white part, which is an unwanted effect, as it makes the beam look far too dim in some situations. Currently it's fixed with some duct tape as a temporary solution (I roughly dubbed a non-transparent white bulk behind the beam so that the dark space can't make the actual texture more dim), but it still needs some work, which I unfortunately don't quite have right now. I'll have some time to play with this perhaps on Monday...
I'm planning to also match the beam edge colours to existing beam-flash animations.
Other thing needing work to be done to it BADLY is the effect which happens when the beam hits something. One possibility would be to expand the hit area's explosion animation, which would hopefully cover the exact spot where the beam hits...

As I said, it needs work to be done with it. I might end up doing two sets of animation frames per picture, even if it doubles the memory used and the amount of files to be downloaded, but it might work better.
Thanks for critique anyway, even though I had already figured those things mostly out It's good that people agree with my own perceptions of beams.
Oh, and the reason why I wouldn't want the center of the beam be
completely white is as follows:
I think the pilots' eyes would be burned into their holes if there wasn't some kind of fastly adaptive filter in the cockpit glass/helmet visor. This filter practically has to dim the beam to viewable brightness levels, much the same way a welder's visor makes it possible to look at sun.
Well, there are brightness differences in the surface of the Sun. We call them sun spots, as they appear dark on the surface when we view them through a telescope with a filter in it.
However, they are not actually much dimmer than the other areas of surface. The reason why we see them dimmer is that eye is an adaptive optic instrument, it adapts to existing brightness differences and applies a "contrast filter", if you like, to separate the small differences and magnify them. This operation takes place in the back of the brains, in the visual cortex.
I believe much the same thing would happen with FS beams. However bright they are, there's bound to be some brightness differences even in the core, and human visual cortex makes them visible much like sun spots.
Regardless, the white areas should actually be white, not just some bright degree of gray but instead as white as the monitor can produce.