You may find the following resources helpful:
The <tt> tag
The <code> tag gives an ugly kind of yellow, probably you will like the look of KDE's better. However since it is intended to be a multi-purpose tag, the syntax is a bit finicky. When <tt> is used inline, it produces monospaced formatting like this. The same effect will happen when <tt> starts a new line. To get a pleasant grey background like <code>, place <tt> in a new line with a space in front of it. You can view the source to see how this works.