Im searching for a chat addon that doesn't have a background alpha.
I've tried prat out but it doesn't fit my needs.. can anyone suggest me a nice lightweight chat addon which doesn't have a background to it..
You don't need an addon to get rid of the chat background. Simply right-click on the chat tab and use the option to change the background color. In the color picker, move the opacity slider on the right to the bottom to make the background completely transparent (invisible). Repeat for any other chat tabs you have.
Most addons do not do anything to the chat frame background, so you should just be able to use whichever chat addon you prefer, or none at all.
PhanxChat (which I wrote) and Chatter are a couple of well-known, lighter-weight alternatives to Prat you could try.