Colloquy is my IRC client of choice since switching to OSX. In busy channels, my screen can be overrun with messages telling me who joined and left the channel. I wanted, not to hide these, but to make them much smaller, and put them all on one line.
It turns out that it’s possible to modify Colloquy’s appearance with CSS. Awesome, CSS and I are old pals. Took me a while to figure it out, but here’s the code.
Open Preferences, then Appearance, then option click Customize Style… and the CSS file will be opened in your editor of choice. Then type
/reload style in a channel to see the new style in action. Here’s the obligatory before and after screenshots.