Yellow,
Just sharing an interesting article for those who likes to read stuff:
http://www.ownedcore.com/forums/world-of-warcraft/world-of-warcraft-guides/324416-psychology-behind-your-ui.html (http://www.ownedcore.com/forums/world-of-warcraft/world-of-warcraft-guides/324416-psychology-behind-your-ui.html)
Happy reading :)
Guru.