Well I'm watching it right now and there are a few color problems which are VERY notable.

The main problem are the "black" borders. The problem is that they're not BLACK :-) They change color from scene to scene. Go to the scene where the stormtroopers invade the blockage runner and when the first one shoots. I expected the frame be white with black borders, instead of it it's pink with red/brown borders :-) And later the color of the borders changes with every scene change, for example every time you cut to the camera angle where the stormtroopers come through the heavy smoke, the borders are lightgrey etc.

Is it possible for you to work only with the "video area" and add the borders at the end ?