With Style Sheets you can change the colours, look and layout of web pages to suit your personal preferences. In some cases Style Sheets can even fix display bugs.
To install a style sheet simply copy the css code and paste it in your usercontent.css file which you can access from the edit>configuration>user-defined stylesheets; save the file and restart K-Meleon. Additionally you can also create a new style with that code for the stylish extension.
List of available style sheets