Hi Karsten
I use to answer like this (alternative way - not any better)
There are sort of color-coding in iMovie
iMovie 1 to HD6 (version 1.0.x - 6.0.4 (3))
Non in special
- Red stripe under the picture (in TimeLine) while rendering
- Yellow marker signs for Chapter Mark
- Green marker signs for Comment Mark
iMovie’08 to 11 (version 7.0.x - 9.0.x)
Violet and White - Most probably connected to Key-notes (Footage has been marked with keywords/s) (People one or many)
Blue band at top - Most probably connected to Key-notes (Footage has been marked with keywords/s) (Panning - Left or Right)
Jaggy red line at bottom - Stabilizing failed in these parts of the clip
Gray boarders (letter-boxed) - Clip was rotated - No real idea Why it is like this
Orange line at the bottom - Clip is part of the selected Project (going on) - if other project is selected the line disappears as Clip is not included in now selected project.
Green line (at top) - Footage has been marked as Favorite
Yellow frame with handles - Clip has been selected and can be trimmed to be shorter in time (at start or end of it)
Red horizontal line (at top) - Rejected Clip
Red vertical line - is the Playhead in the TimeLine view
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Red line in Audio portion - NO IDEA ?
Red ontop of the Yellow only indicates that Audio level is too strong and in need to be decreased - but it use to play with more or less distorsion (very unpleasant)
Red vertical line - is the Playhead in the TimeLine view
iMovie’13 (version 10.0.x)
Have no idea
Yours Bengt W