From the film screening of the pre-SE print of The Empire Strikes Back (excellent pictures from which can be seen in that thread I gave a link to above), it can be seen that on Hoth that indeed Hoth has always had a icey bluish color to it. So that is the correct color it should be in any restoration of the colors in the GOUT.

Of course, in other scenes in the SE, it may be more blue that it's supposed to be. That's why those pictures from the real films in that thread here are so great, you can see the real correct colors in various scenes and what they should be in the GOUT. :)