[Dylan Murphy]"Say I am working in FCP and if a clip needs rendering and it is the bright green color (preview) does it need to be rendered if going out to compressor for DVD? "
No. If you export via Compressor, rendering isn't necessary. FCP will export without rendering first.
[Dylan Murphy]"or does it need rendering if its going to be exported a .mov etc."
If you export a QT movie, self contained...or reference...using EXPORT>QT MOVIE... it will need to be rendered. or FCP will render before it exports...but that render exists ONLY on that export, not the timeline.
[Dylan Murphy]"Is there a list somewhere describing what exactly needs to be rendered in certain situations?"
Everything that has a color above it...other than dark purple...needs to be rendered. Unless you export via Compressor. But then that ties up FCP while it exports.
[Dylan Murphy]"Is it only red (needs render) that needs to be done in order to export?"
[Dylan Murphy]"Or will the export take longer if the clip is not rendered? "