Ok let me try to explain this so it will work like you want it too.
You are going to have to understand how to edit the ui file to get a handle for getting the alpha animation to work with the accout list. As seen here ...
logonaccount
{
cursor: hand;
foreground: rgb(239,153,102);
background: rgb(196,188,188);// rgb(48,70,179);
animation: /*LogonAnimation1*/ alpha | log | fast;
alpha:96; // mouse within
thus the logon animation1
then there is another animation logon animation2 to give it a full and/or no trans seen here...
logonaccount [logonstate=1]
{
animation: /*LogonAnimation2*/ rectangle | s | mediumfast;
cursor: arrow;
alpha:255; //????
notice the alpha settings and how it will say it gives 2 animation effects.
This will control the bitmap 112 and you can use whatever background for that area as you wish. With or without pink..
I would not use pink - I prefer using a 32bit bitmap image with alpha channels. But as I said it is up to the person to understand their own code and it works with what they are trying to do with the ui file to make the logon work correctly.
This feature for XP logons has no editor! If edited with Logon Studio the features will be rewritten to the base format for Logon Studio. Thus erasing anything done outside of the basic scope of the program itself.
Here is a fair type of reference for reading as to what the ui file is and how it is written. But be aware all code is still being developed for logons everyday we use them. To really understand it you must try the code yourself to see it in action and then see if you want to change it for your purpose. Here is the link...
http://doc.trolltech.com/3.3/designer-manual-16.html
This is not for the logon studio code - but is a base for all the ui type files coding. In the past I have found there is no base for the code and it will be written over and over to suite the maker of whatever logon we design. In short with the right code you can make your images work as you want them too and just about do whatever is possible with anything in the logon.
Look at this to get your ideas and then open that marine 2 logon ui file and see what he did with his logon. I have found that a good editor is needed to do such a thing also with any and all ui files. Such as Notepad ++ found here at this link
http://notepad-plus.sourceforge.net/uk/site.htm
get the excutable file for install on win xp. not the source files...
with this editor if there is an error code presented by your logon because of a bad ui entry into the code - it will usually say as to what line it is on and you will be able to easily find it with this editor.
I wish you luck on your logon and can't wait to see the finished product. Do contact me if I can be of any futher help to you.