Finally, after years of waiting, the BBC will be releasing the Third Doctor story, The Ambassadors of Death, on DVD in color. Color prints of the story no longer exist apart from episode one. Only B&W prints exist for the remaining 6 episodes. Work had been done, using inferior off air color copies to restore episodes 5&6 but technology has finally advanced enough to complete the color restoration. The DVD is planned for later this year.
Here are some comparisons of the original color prints and the restoration -