Those are two different causes shown in your graphic.
The blue are part markers. A measure can be blue (A), green (B) or no color. A few styles are multistyles and allow many more colors. I suppose you could create a dummy multistyle with the same patterns, and use that just for colors.
The red underscores are the indicator from BIAB that some editing of that measure was done by F5. You can press F5 on a measure and you will see that something was changed: the tempo, volume, muting of an instrument, the style, or many other possible settings.
I didn't make myself clear.
Those red lines were drawn by me with software.
I want to turn those frames into all red or blue. My goal is to open them next time and see the marks because those chords are special.