BuddhaMaster said:

And then someone said a trailer does not represent a final look of a movie. That is to say they do additionally re-grade a trailer to show off? They do show a movie-preview with a different color than the final release?

Seriously that is questionable.

Why so much pandering? Is everyone so insecure.

When a trailer is made, especially one that is shown up to a year before the film comes out, then the chances are that the film grading hasn't even begun yet. The clips are assembled and then the grading is done. These clips could be in their raw ungraded state. And , like i said before,most likely not by the same person who would be grading the final film . This is why the grading ends up looking different in the final film. Even back when Star Wars showed its very first trailer, the grading was different than what we saw in the final film. It's not a new thing. So, no, they don't additionally regrade a trailer just to show off at all.