At the moment I'm using a 16-point white ariel font with black outline for my subtitles. They tend to flicker/shimmer on a CRT (PAL). Any suggestions for reducing the flicker?
The colors for subtitles are controlled by color sets. By default, all subtitles use Color Set #4 -- so in order to change the colors for subtitles, edit Color Set 4.
Select a subtitle event, and the Properties window will display the properties for that event. Choose the Color Sets tab and adjust as needed.