First question: no, I think that's hard coded - meaning you can't remove it.
Second question: you would have to fix the colors first (not have them customisable by users) and then use the following:
In the left hand part of the custom code box, type glowtext, then in the right hand part of the box, type the following:
<table style="filter:GLOW(color=#CB59E3, strength=4)">
<tr><td><font color="#FFFFFF" size="2">
Now that's the opening tag; you now have to close it, like this:
Start up another custom code and in the left hand part of the box, type /glowtext. Then type the following in the right hand part:
That will now set up the BbCode for glowing text.