Hi
Interesting question. Can You Please - make a screen-dump and include it - so I / We can see it. I can only find Wavy red lines at bottom of my imported clips = Image Stabilization failed in these parts.
Orange at bottom of Clip in Even't = Clip is included in ongoing Project in TimeLine.
But I found to my surprise other interesting colored bands - that I have no idea what they mean either
Blue/White - along top side of Clip (not contineous but longer and shorter parts - ??????
Violet/White - also at top and discontinuing - ????
And a rotated Clip that (standing) got Gray letter-boxing - a. Black I could understand - and when Standing on the sides OK - but top and bottom - ??????
Have to dive into this mystery - and see if there is Color info in iMovie 1 to HD6 too - and what has happened in iMovie'13 (vers. 10) ?
Yours very interested - Bengt W