In terms of the color comparisons, it's important to remember that the color differences aren't necessarily due to fading. In the early to mid 80s, the film would not have been fading yet, at least not visibly. The color issues are more due to how the color was timed in the video transfer. Most of the pre-SE transfers of the trilogy (especially the first two) had a desaturated, low-contrast, overly bright look. (I think Jedi was always the closest, but even it looked too warm; compare the official video transfers to the clips in the 80s documentaries.)
A lot of 80s video transfers had that in common; I think it was so the image would read better on standard TV sets?
The THX transfers had a higher-contrast look (maybe too high - witness the clipped whites), but they were still desaturated and still not accurate to how the films looked in theaters.
The ITV transfer was not "properly" timed for home video; it was reminds me of TV film-chain, and it was likely transferred in-house, as the U.S. TV networks did before they started receiving ready-made video transfers from the studios.
That green-gray look is probably because the color was not adjusted too much in the video realm. Notice you can see color detail that's not in the home video releases.
Luke's skin color in the ITV frame may be closest out of the three to the theatrical prints - from what I can tell, skin tones in the original timing were more orange than pink, and Mark Hamill seems to have had a decent tan anyway.
