Break appart movie clip/change color

So I’m making a weird little dungeon generator and I was wondering if the following was in any way possible:
all the walls are duplicated movieclips and are basically generated like this:

_root.wallPrefab.duplicateMovieClip(_root["walls.wall"+i], depthwhatever);
var changecolor = new Color(_root.walls.wall0);
changecolor.setRGB("0xFF0000");

which seems to create _root.walls.wall0 and up perfectly, but the colour stays black, as if setRGB doesn’t work in parented movieclips (or does it?).
if this is the case, is there a way to “ctrl-b” wall 0 t/m 40 inside the walls object in as2 after generating and leave behind the vectors? This could save some resources hittesting as I’d only have to check the single walls parent object and not check every single wall with a for loop, and give better control over the colour.