I have a video of mixed aspect ratio files (some regular def, and some high-def/wide screen) . When I import the widescreen files into my project, a black bar is put atop and below my video (which is fine). Can I change the color of that black bar to something else? Can I change the color of the black bar per clip? (i.e. clip one black bar color change would be blue, clip two would be yellow, clip three green, etc). Thank you.