I personally think that all TIE Fighters in the OT should be grey (similar to ANH) and not blue; the colour that the imperials use on their ships is in fact grey, as visible on the star destroyers. Besides, grey looks a lot better on TIE fighters as seen in A New Hope, and we'll also want to keep the colour consistant for all episodes.

Another 'blue' object I think should be recoloured back to grey is the Executor itself, especially when viewed in contrast to the smaller star destroyers. I tihnk the executor should be recoloured to grey even if that is not how it originally appeared.