The reason they're still around is because Chise is too lazy to take them out. Often times, when a person uses a font that's hard to see, and people complain about it, I usually step in and change their default color to one that's a little easier to see, but at the same time, keep it so that it's only a darker shade of the person's original color, usually about half to 2/3 of what the original was, depending on the intensity of the original color.
As for just over all colors, we just need to wait for Chise to take them out. With the exception of white, all the other extremely bright colors don't really have a use, other than to troll and piss people off, so we'll just have to pester Chise until he takes care of it.
:tea:
And yes, white is awesome for spoilering stuff :I