I liked Octorox's mock-up of a potentially greener-Dagobah. By colouring the planet seen in ESB green, as opposed to dropping in the planet seen in ROTS, it still retains that murkiness, that cloud-cover, which would result in Luke's X-Wing equipment going hay-wire when he enters the atmosphere. It would just have a more over-all greenish tint to it. Due to the samey-ness of the planets in ESB, I'd be for colouring Dagobah slightly greener than it currently is - maybe even changing the colour of the atmosphere-glow-line-around-the-planet from blue to green as well, just to subtly indicate the differences in environment between Dagobah and Hoth and Bespin.