I'll grant you the still shot of the green planet looks overly washed out, but watching the two recent trailers again I don't see any sign of this problem. The effects shots all look perfectly fine, with bold colors, lots of contrast and no obvious matte lines that I can see.
The footage in the trailers have often been doctored up, have they not? I wouldn't trust them to be an accurate representation of what the blurays will actually look like.
There seems to be a lot of 'the actual blurays will look better than the screen shots' talk, yet any of the still screen shots from Season 1 looked just as good as the actual blurays. I get it, people are trying to be hopeful...but there comes a time when you have to face the reality of the situation. It just doesn't look as good.