When and why would an audio region appear transparent? The grid show through and there is no background colour behind the waveform. I am able to assign a colour to all tracks, and to all regions except this one. I have a small project with about 10 audio tracks, a mix of mono and stereo. The audio region in the project browser list of audio files has an assigned colour but the colour is not applied in the main edit page. I can't see differences in the status of this region or track compared to all others in the project. All are unhidden, unmuted, active, not in record status, etc. The only difference is a small round coloured dot in the upper left hand corner of the region.