ratpack1961 said:
That matte painting behind Han and Lando with the falcon is maybe the worst effect in the OT. It's not an error per se but a real error in judgement!
It is mostly the colours on the SE DVDs/BluRays that are off. The background does not have a blue tint all over it in the original version.
When Lando turns around and moves towards the Falcon, he steps out of the light on the greenscreen set turning him into a black silhouette. Also, it is clear that the other people in that shot have been composited in, because a couple of them would have collided with ghost-Lando ...