My 5-year-old son noticed something in The Empire Strikes Back: When the Millenium Falcon takes off from Bespin (Cloud City) the light from the engines is red. In all other images it appears blue. Is there an explanation for that?
Although it's worth pointing out that the Falcon's engines do show a variety of colours (ranging from light blue through to a vivid white, tinged with pink) depending on their power output. In this particular instance though, then tiny on the engines would appear to be a function of the red-tinted atmosphere of the gas giant. What you're looking at is the usual white engine glow viewed through a red filter.
You can also see the red glow as the ship comes in to land (or whenever it's flying around Bespin).