Now what would make you read this guide without me making it more interesting than just posting my status. It is time to present you some "tricks" about my work, starting with (because I consider this to be senseful) my new chats.
First of all remember that I'm just presenting you the way I did it. Feel free to change colors, opacitys, sizes etc.
So actually what you need is kgpanels, download it at curse.com or whereever.
You will have to use 3 panels in order to get the same effect like me. The first panel is just a black one, 100% opacity, size a bit bigger than the chat is. The level can be set to 1.
The second panel on level 2 needs to be a very bit smaller than the first one to be able to cover the black one, in order to only have a small black line around your chat (which means 2-3 pixels less width). I know this could probably be realised by an easy border, but since kgpanels seems to be unable to create some equal borders at each side I made it this way.
You may set the color to any color you want, I took (0.13, 0.14, 0.15, 100%). Furthermore you need a background texture which you can download here. Many thanks to Caith at this point, from whom I borrowed the grapic.
The third panel is once again smaller than the second one, I took around 10 pixels compared to the second one. Set the level to 3, same color as for the last one (0.13, 0.14, 0.15, 100%), same texture, the only difference is I used a border texture now, named "Blizzard dialog", order edge size 4, border insets set to 0. Now put one on top of each other - you're done!
One further tip at the end: anchor the panels to the first one. This will make it much easier for you to position and modify them.